Lateral Patellofemoral Ligament Reconstruction Using a Quadriceps Tendon Graft Michael G. Saper, D.O., A.T.C., C.S.C.S., and David A. Shneider, M.D.
Abstract: Medial patellar subluxation (MPS) is normally described after a lateral retinacular release. However, isolated MPS in the absence of a previous lateral release does occur. This type of patellar instability is often overlooked, and a high index of suspicion is needed for appropriate diagnosis and treatment. This report describes a technique developed in response to episodes of isolated MPS. The technique uses a partial-thickness graft from the quadriceps tendon to reconstruct the lateral patellofemoral ligament and provide stability to the lateral side of the patella.
M
edial patellar instability is a disabling condition that can limit daily functional activities because of apprehension and pain. The instability is influenced by a variety of factors that allow the patella to translate medially and ultimately subluxate or dislocate to the medial side. In patients with normal trochlear and patellar osseous anatomy and lower extremity alignment, the patellar instability results from insufficient passive soft-tissue stabilizers.1,2 Several reports are found in the literature describing this condition and its association with failed lateral retinacular release.3-9 Surgical options to address the problem include repair of the lateral retinaculum with imbrication,6,7 reconstruction with local soft-tissue augmentation,3 and lateral patellofemoral ligament (LPFL) reconstruction.8,9 However, there is limited literature describing isolated medial patellar subluxation (MPS) in the absence of a previous lateral release. Only a few reports have been published regarding the findings and treatment outcomes.10,11 Our technique was developed for the management of patients with isolated MPS. The technique uses a From the Department of Osteopathic Surgical Specialties, Michigan State University (M.G.S.), East Lansing; Department of Orthopaedic Surgery, McLaren Greater Lansing (M.G.S., D.A.S.), Lansing; and Mid-Michigan Orthopaedic Institute (D.A.S.), East Lansing, Michigan, U.S.A. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received February 11, 2014; accepted April 17, 2014. Address correspondence to Michael G. Saper, D.O., A.T.C., C.S.C.S., Department of Orthopaedic Surgery, McLaren Greater Lansing, 2727 S Pennsylvania Ave, Lansing, MI 48910, U.S.A. E-mail: Michael.saper@ mclaren.org Ó 2014 by the Arthroscopy Association of North America 2212-6287/14117/$36.00 http://dx.doi.org/10.1016/j.eats.2014.04.007
partial-thickness graft from the quadriceps tendon to reconstruct the LPFL and provide stability to the lateral side of the patella. An advantage of this technique is that it avoids bone tunnels, screws, and anchors in the patella, thereby avoiding the risk of patellar fracture. We describe our technique in this report. Table 1 describes the pearls, indications, and pitfalls of this technique.
Surgical Technique The patient is examined under anesthesia to confirm the diagnosis of medial patellar instability (Video 1). Lateral forces are applied to the patella in full knee extension and 30 of flexion. A tourniquet is placed on the thigh, and the patient is then positioned supine with the surgical limb secured in a leg holder. Diagnostic arthroscopy is routinely performed, and intra-articular findings are noted (Fig 1). The patellofemoral joint, in addition to the medial and lateral compartments, is evaluated for the presence of chondral injuries. Chondroplasty is performed as needed, and loose bodies are removed. Associated meniscal pathology is addressed as indicated. A midline skin incision is then made, and skin flaps are developed to expose the patella and patellar mechanism from 5 cm above the patella to the tibial tubercle. Hemostasis is obtained with electrocautery. A lateral release and tibial tubercle transfer may be performed if indicated to center the patella in the trochlea. If used, the lateral release is repaired by rotating a flap of tissue from the adjacent iliotibial band to close the defect. This prevents the development of lateral-side laxity and allows the reconstructed ligament to be optimally tensioned. Next, the appropriate location for the LPFL femoral attachment at the lateral epicondyle is
Arthroscopy Techniques, Vol 3, No 4 (August), 2014: pp e445-e448
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Table 1. Tips, Pearls, Indications, and Pitfalls Tips and pearls The surgeon should ensure balanced tracking of the patella in the femoral trochlea first using a lateral release and tibial tubercle transfer selectively. Once the tibial tubercle is fixed in the corrected position, the lateral release is repaired by rotating a flap of tissue from the adjacent iliotibial band to close the defect. This prevents development of lateral-side laxity. An arthroscopic leg holder should be used for all portions of the case. The surgeon should ensure a long enough incision with adequate skin flaps to palpate appropriate femoral landmarks. Indications Isolated MPS MPS after lateral release Pitfalls Failure to correct underlying malalignment Failure to accurately identify LPFL attachment site Over-tensioning of graft
identified, and a 1-cm incision is made at that site to allow for anchor placement. The quadriceps tendon is visualized, and its medial and lateral borders are identified. The graft length is estimated by measuring the distance from the superior pole of the patella to the lateral epicondyle. A partial-thickness graft is harvested from the central third of the quadriceps tendon, leaving its patellar insertion intact. The graft is taken from the most superficial layer of the tendon, and dissection is carried proximally enough to ensure that the graft is of sufficient length (Fig 2). Next, the graft is cut proximally, and sharp dissection is continued distally to the patellar insertion. The dissection is typically carried further distally on the medial aspect of the graft so that the graft lies flush once it is turned. The graft is prepared with No. 2 FiberLoop (Arthrex, Naples, FL) using the SpeedWhip (Arthrex) technique in the free end to be used for the lateral femoral attachment. A tunnel is created in the lateral retinaculum from the edge of the
quadriceps tendon to the lateral epicondyle (Fig 3). The quadriceps graft is then turned 90 laterally and twisted 180 . The free ends of the loop suture and proximal end of the graft are passed through the tunnel, exiting at the epicondyle (Fig 4). The graft is then secured to the LPFL attachment site with a 4.75-mm 24.5-mm BioSwiveLock SP suture anchor (Arthrex) (Fig 5). Proper graft tension is obtained by holding the knee in 60 of flexion with the patella reduced in the trochlea. The excess suture is removed and the iliotibial band repaired over the insertion point. Quadriceps contraction is simulated with a towel clip to verify full excursion, and the graft is confirmed to be isometric. Repeat arthroscopy is performed, showing the patella to be centered and stable (Fig 6). The fascial and skin incisions are closed, and the patient is placed in a knee immobilizer. Postoperatively, the patient is admitted for observation, educated on active range-of-motion and quadriceps exercises, and discharged from the hospital the following day. The patient is encouraged to bear weight as tolerated with crutches for 2 to 4 weeks. Use of the knee immobilizer is discontinued when the patient has gained good quadriceps control.
Discussion Medial subluxation of the patella, as described in the literature, is found either in isolation or in association with a previous lateral release.3-11 The recognition and treatment of isolated MPS may be difficult. Isolated MPS is identified clinically by increased passive medial patellar mobility, a positive medial patellar apprehension test, and demonstrable MPS or frank dislocation when manual pressure is applied to the lateral patella.4,5,7 Patellar maltracking visualized from the anterolateral portal during diagnostic arthroscopy confirms the diagnosis. The patella sits medial to the trochlear groove until the knee is flexed to approximately 40 .
Fig 1. Preoperative arthroscopic images of patellofemoral compartment (left knee) viewed from anterolateral portal showing 2þ lateral patellar laxity at (A) full knee extension and (B) MPS at 30 of knee flexion.
LPFL RECONSTRUCTION
Fig 2. View of left knee after midline skin incision. A partialthickness graft, taken from the most superficial layer of the tendon, is harvested from the central third of the quadriceps tendon, leaving its patellar insertion intact. Dissection is carried proximally enough to ensure that the graft is of sufficient length.
At that point, the patella has slid laterally into the trochlear groove and remains there through the remainder of knee flexion. Shellock et al.12 used kinetic magnetic resonance imaging of the patellofemoral joint to evaluate patients with persistent symptoms after lateral release. They noted that MPS might be an unrecognized condition in patients with patellar maltracking. Of 40 patients who had a previous lateral release, 17 (43%) showed MPS in the nonoperative knee. The authors suspected that MPS may have been present before the lateral retinacular release but was not recognized in these patients. There are a limited number of reported cases of medial patellar instability in patients without previous lateral release. Richman and Scheller10 presented the case of a 17-year-old patient with persistent right patellofemoral joint complaints found to have isolated medial subluxation of the patella. Imbrication of the patient’s lateral patellar retinaculum centralized patellar tracking and stabilized the patella. Shannon and Keene11 reported 2 cases of recurrent medial subluxation of the patella that occurred spontaneously. Both
Fig 3. A subfascial tunnel is created in the lateral retinaculum with a clamp from the edge of the quadriceps tendon to the LPFL attachment site at the lateral epicondyle.
e447
Fig 4. The end of the graft is secured with a No. 2 loop suture. The graft is then turned 90 laterally, twisted 180 , and passed through the subfascial tunnel with a passing suture.
cases were treated with arthroscopic medial retinacular release. At a mean follow-up of 2.7 years, both medial subluxation and knee pain were relieved. Several anatomic factors should be considered, although considerable variation exists. The quadriceps tendon includes contributions from the rectus femoris superficially, the vastus medialis and vastus lateralis intermediately, and the vastus intermedius deeply. The LPFL is located in the second layer of the lateral aspect of the knee.13 The LPFL originates from the lateral femoral epicondyle and inserts onto the lateral aspect of the patella.14 Teitge and Torga Spak8 described a technique for LPFL reconstruction using the patient’s own quadriceps tendon as a salvage procedure for repair of medial iatrogenic instability. In their experience, direct repair or imbrication of the lateral retinaculum failed to provide long-term stability because medial excursion usually appeared after 1 year. Their technique harvests a free graft that includes a portion of the quadriceps tendon, as well as an attached 1-cm2 5-mm-thick bone block removed from the superior central one-third of the patella. The bone block is placed in a recessed bony bed at the femoral epicondyle and secured with a 4.0-mm lag screw. The technique also requires 2 parallel 4.5- to 6-mm bone tunnels in the patella. The authors reported excellent results with no cases of recurrent instability;
Fig 5. The graft is fixed to the LPFL attachment at the lateral epicondyle with a knotless anchor.
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M. G. SAPER AND D. A. SHNEIDER
have been promising. In all cases the patella was stable with no residual medial subluxation after an average of 1 year of follow-up. There have been no cases of patellar fracture, quadriceps tendon rupture, or infection. Outcome studies are in progress.
References
Fig 6. Postoperative arthroscopic image of the patellofemoral articulation, viewed from the lateral portal (left knee), showing a stable patella, centered in the trochlea.
however, they noted patellar fractures in 3 of 60 patients that required open reduction and internal fixation. Our technique of LPFL reconstruction makes use of a quadriceps tendon graft in a fashion similar to that described by Steensen et al.15 As in their technique, the graft is detached proximally but remains attached distally so that the surgeon is required to free and secure only 1 side. The technique preserves the insertion of the graft on the patella near the normal patellar attachment of the LPFL. This enables the reconstructed ligament to function isometrically so that it will be effective through the greatest range of motion. The technique also avoids a patellar bone block and does not require drill holes through the patella, thereby eliminating the risks of patellar fracture and damage to the articular surface. The results of the medial patellofemoral ligament technique of Steensen et al.16 were promising, with good or excellent results achieved in 100% of patients and with no episodes of patellar dislocation at a mean of 42 months postoperatively. In summary, there are a limited number of reported cases of isolated MPS. This type of patellar instability might not be as rare as previously thought. It can be a subtle problem, often overlooked, and difficult to diagnose. A high index of suspicion is needed for appropriate diagnosis and treatment. LPFL reconstruction with a quadriceps tendon graft is a simple procedure with little associated morbidity. The technique is effective in preventing further episodes of instability and improving quality of life. A clear advantage of using the quadriceps tendon is the avoidance of bone tunnels, screws, and anchors in the patella, thereby avoiding the risk of patellar fracture. The senior author has performed the described technique in 3 patients with isolated MPS. Early results
1. Kramers-de Quervain IA, Biedert R, Stüssi E. Quantitative gait analysis in patients with medial patellar instability following lateral retinacular release. Knee Surg Sports Traumatol Arthrosc 1997;5:95-101. 2. Sanchis-Alfonso V, Torga-Spak R, Cortes A. Gait pattern normalization after lateral retinaculum reconstruction for iatrogenic medial patellar instability. Knee 2007;14: 484-488. 3. Abhaykumar S, Craig DM. Fascia lata sling reconstruction for recurrent medial dislocation of the patella. Knee 1999;6:55-57. 4. Hughston JC, Deese M. Medial subluxation of the patella as a complication of lateral retinacular release. Am J Sports Med 1988;16:383-388. 5. Hughston JC, Flandry F, Brinker MR, Terry GC, Mills JC III. Surgical correction of medial subluxation of the patella. Am J Sports Med 1996;24:486-491. 6. Johnson DP, Wakeley C. Reconstruction of the lateral patellar retinaculum following lateral release: A case report. Knee Surg Sports Traumatol Arthrosc 2002;10:361-363. 7. Nonweiler DE, DeLee JC. The diagnosis and treatment of medial subluxation of the patella after lateral retinacular release. Am J Sports Med 1994;22:680-686. 8. Teitge RA, Torga Spak RT. Lateral patellofemoral ligament reconstruction. Arthroscopy 2004;20:998-1002. 9. Udagawa K, Niki Y, Matsumoto H, et al. Lateral patellar retinaculum reconstruction for medial patellar instability following lateral retinacular release: A case report. Knee 2014;21:336-339. 10. Richman NM, Scheller AD Jr. Medial subluxation of the patella without previous lateral retinacular release. Orthopedics 1998;21:810-813. 11. Shannon BD, Keene JS. Results of arthroscopic medial retinacular release for treatment of medial subluxation of the patella. Am J Sports Med 2007;35:1180-1187. 12. Shellock FG, Mink JH, Deutsch A, Fox JM, Ferkel RD. Evaluation of patients with persistent symptoms after lateral retinacular release by kinematic magnetic resonance imaging of the patellofemoral joint. Arthroscopy 1990;6:226-234. 13. Waligora AC, Johanson NA, Hirsch BE. Clinical anatomy of the quadriceps femoris and extensor apparatus of the knee. Clin Orthop Relat Res 2009;467:3297-3306. 14. Navarro MS, Navarro RD, Akita Junior J, Cohen M. Anatomical study of the lateral patellofemoral ligament in cadaver knees. Rev Bras Ortop 2008;43:300-307. 15. Steensen RN, Dopirak RM, Maurus PB. A simple technique for reconstruction of the medial patellofemoral ligament using a quadriceps tendon graft. Arthroscopy 2005;21:365-370. 16. Dopirak R, Adamany D, Bickel B, Steensen R. Reconstruction of the medial patellofemoral ligament using a quadriceps tendon graft: A case series. Orthopedics 2008;31:217.
Abstract: Medial patellar subluxation (MPS) is normally described after a lateral retinacular release. However, isolated MPS in the absence of a previous lateral release does occur. This type of patellar instability is often overlooked, and a high index of suspicion is needed for appropriate diagnosis and treatment. This report describes a technique developed in response to episodes of isolated MPS. The technique uses a partial-thickness graft from the quadriceps tendon to reconstruct the lateral patellofemoral ligament and provide stability to the lateral side of the patella.
M
edial patellar instability is a disabling condition that can limit daily functional activities because of apprehension and pain. The instability is influenced by a variety of factors that allow the patella to translate medially and ultimately subluxate or dislocate to the medial side. In patients with normal trochlear and patellar osseous anatomy and lower extremity alignment, the patellar instability results from insufficient passive soft-tissue stabilizers.1,2 Several reports are found in the literature describing this condition and its association with failed lateral retinacular release.3-9 Surgical options to address the problem include repair of the lateral retinaculum with imbrication,6,7 reconstruction with local soft-tissue augmentation,3 and lateral patellofemoral ligament (LPFL) reconstruction.8,9 However, there is limited literature describing isolated medial patellar subluxation (MPS) in the absence of a previous lateral release. Only a few reports have been published regarding the findings and treatment outcomes.10,11 Our technique was developed for the management of patients with isolated MPS. The technique uses a From the Department of Osteopathic Surgical Specialties, Michigan State University (M.G.S.), East Lansing; Department of Orthopaedic Surgery, McLaren Greater Lansing (M.G.S., D.A.S.), Lansing; and Mid-Michigan Orthopaedic Institute (D.A.S.), East Lansing, Michigan, U.S.A. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received February 11, 2014; accepted April 17, 2014. Address correspondence to Michael G. Saper, D.O., A.T.C., C.S.C.S., Department of Orthopaedic Surgery, McLaren Greater Lansing, 2727 S Pennsylvania Ave, Lansing, MI 48910, U.S.A. E-mail: Michael.saper@ mclaren.org Ó 2014 by the Arthroscopy Association of North America 2212-6287/14117/$36.00 http://dx.doi.org/10.1016/j.eats.2014.04.007
partial-thickness graft from the quadriceps tendon to reconstruct the LPFL and provide stability to the lateral side of the patella. An advantage of this technique is that it avoids bone tunnels, screws, and anchors in the patella, thereby avoiding the risk of patellar fracture. We describe our technique in this report. Table 1 describes the pearls, indications, and pitfalls of this technique.
Surgical Technique The patient is examined under anesthesia to confirm the diagnosis of medial patellar instability (Video 1). Lateral forces are applied to the patella in full knee extension and 30 of flexion. A tourniquet is placed on the thigh, and the patient is then positioned supine with the surgical limb secured in a leg holder. Diagnostic arthroscopy is routinely performed, and intra-articular findings are noted (Fig 1). The patellofemoral joint, in addition to the medial and lateral compartments, is evaluated for the presence of chondral injuries. Chondroplasty is performed as needed, and loose bodies are removed. Associated meniscal pathology is addressed as indicated. A midline skin incision is then made, and skin flaps are developed to expose the patella and patellar mechanism from 5 cm above the patella to the tibial tubercle. Hemostasis is obtained with electrocautery. A lateral release and tibial tubercle transfer may be performed if indicated to center the patella in the trochlea. If used, the lateral release is repaired by rotating a flap of tissue from the adjacent iliotibial band to close the defect. This prevents the development of lateral-side laxity and allows the reconstructed ligament to be optimally tensioned. Next, the appropriate location for the LPFL femoral attachment at the lateral epicondyle is
Arthroscopy Techniques, Vol 3, No 4 (August), 2014: pp e445-e448
e445
e446
M. G. SAPER AND D. A. SHNEIDER
Table 1. Tips, Pearls, Indications, and Pitfalls Tips and pearls The surgeon should ensure balanced tracking of the patella in the femoral trochlea first using a lateral release and tibial tubercle transfer selectively. Once the tibial tubercle is fixed in the corrected position, the lateral release is repaired by rotating a flap of tissue from the adjacent iliotibial band to close the defect. This prevents development of lateral-side laxity. An arthroscopic leg holder should be used for all portions of the case. The surgeon should ensure a long enough incision with adequate skin flaps to palpate appropriate femoral landmarks. Indications Isolated MPS MPS after lateral release Pitfalls Failure to correct underlying malalignment Failure to accurately identify LPFL attachment site Over-tensioning of graft
identified, and a 1-cm incision is made at that site to allow for anchor placement. The quadriceps tendon is visualized, and its medial and lateral borders are identified. The graft length is estimated by measuring the distance from the superior pole of the patella to the lateral epicondyle. A partial-thickness graft is harvested from the central third of the quadriceps tendon, leaving its patellar insertion intact. The graft is taken from the most superficial layer of the tendon, and dissection is carried proximally enough to ensure that the graft is of sufficient length (Fig 2). Next, the graft is cut proximally, and sharp dissection is continued distally to the patellar insertion. The dissection is typically carried further distally on the medial aspect of the graft so that the graft lies flush once it is turned. The graft is prepared with No. 2 FiberLoop (Arthrex, Naples, FL) using the SpeedWhip (Arthrex) technique in the free end to be used for the lateral femoral attachment. A tunnel is created in the lateral retinaculum from the edge of the
quadriceps tendon to the lateral epicondyle (Fig 3). The quadriceps graft is then turned 90 laterally and twisted 180 . The free ends of the loop suture and proximal end of the graft are passed through the tunnel, exiting at the epicondyle (Fig 4). The graft is then secured to the LPFL attachment site with a 4.75-mm 24.5-mm BioSwiveLock SP suture anchor (Arthrex) (Fig 5). Proper graft tension is obtained by holding the knee in 60 of flexion with the patella reduced in the trochlea. The excess suture is removed and the iliotibial band repaired over the insertion point. Quadriceps contraction is simulated with a towel clip to verify full excursion, and the graft is confirmed to be isometric. Repeat arthroscopy is performed, showing the patella to be centered and stable (Fig 6). The fascial and skin incisions are closed, and the patient is placed in a knee immobilizer. Postoperatively, the patient is admitted for observation, educated on active range-of-motion and quadriceps exercises, and discharged from the hospital the following day. The patient is encouraged to bear weight as tolerated with crutches for 2 to 4 weeks. Use of the knee immobilizer is discontinued when the patient has gained good quadriceps control.
Discussion Medial subluxation of the patella, as described in the literature, is found either in isolation or in association with a previous lateral release.3-11 The recognition and treatment of isolated MPS may be difficult. Isolated MPS is identified clinically by increased passive medial patellar mobility, a positive medial patellar apprehension test, and demonstrable MPS or frank dislocation when manual pressure is applied to the lateral patella.4,5,7 Patellar maltracking visualized from the anterolateral portal during diagnostic arthroscopy confirms the diagnosis. The patella sits medial to the trochlear groove until the knee is flexed to approximately 40 .
Fig 1. Preoperative arthroscopic images of patellofemoral compartment (left knee) viewed from anterolateral portal showing 2þ lateral patellar laxity at (A) full knee extension and (B) MPS at 30 of knee flexion.
LPFL RECONSTRUCTION
Fig 2. View of left knee after midline skin incision. A partialthickness graft, taken from the most superficial layer of the tendon, is harvested from the central third of the quadriceps tendon, leaving its patellar insertion intact. Dissection is carried proximally enough to ensure that the graft is of sufficient length.
At that point, the patella has slid laterally into the trochlear groove and remains there through the remainder of knee flexion. Shellock et al.12 used kinetic magnetic resonance imaging of the patellofemoral joint to evaluate patients with persistent symptoms after lateral release. They noted that MPS might be an unrecognized condition in patients with patellar maltracking. Of 40 patients who had a previous lateral release, 17 (43%) showed MPS in the nonoperative knee. The authors suspected that MPS may have been present before the lateral retinacular release but was not recognized in these patients. There are a limited number of reported cases of medial patellar instability in patients without previous lateral release. Richman and Scheller10 presented the case of a 17-year-old patient with persistent right patellofemoral joint complaints found to have isolated medial subluxation of the patella. Imbrication of the patient’s lateral patellar retinaculum centralized patellar tracking and stabilized the patella. Shannon and Keene11 reported 2 cases of recurrent medial subluxation of the patella that occurred spontaneously. Both
Fig 3. A subfascial tunnel is created in the lateral retinaculum with a clamp from the edge of the quadriceps tendon to the LPFL attachment site at the lateral epicondyle.
e447
Fig 4. The end of the graft is secured with a No. 2 loop suture. The graft is then turned 90 laterally, twisted 180 , and passed through the subfascial tunnel with a passing suture.
cases were treated with arthroscopic medial retinacular release. At a mean follow-up of 2.7 years, both medial subluxation and knee pain were relieved. Several anatomic factors should be considered, although considerable variation exists. The quadriceps tendon includes contributions from the rectus femoris superficially, the vastus medialis and vastus lateralis intermediately, and the vastus intermedius deeply. The LPFL is located in the second layer of the lateral aspect of the knee.13 The LPFL originates from the lateral femoral epicondyle and inserts onto the lateral aspect of the patella.14 Teitge and Torga Spak8 described a technique for LPFL reconstruction using the patient’s own quadriceps tendon as a salvage procedure for repair of medial iatrogenic instability. In their experience, direct repair or imbrication of the lateral retinaculum failed to provide long-term stability because medial excursion usually appeared after 1 year. Their technique harvests a free graft that includes a portion of the quadriceps tendon, as well as an attached 1-cm2 5-mm-thick bone block removed from the superior central one-third of the patella. The bone block is placed in a recessed bony bed at the femoral epicondyle and secured with a 4.0-mm lag screw. The technique also requires 2 parallel 4.5- to 6-mm bone tunnels in the patella. The authors reported excellent results with no cases of recurrent instability;
Fig 5. The graft is fixed to the LPFL attachment at the lateral epicondyle with a knotless anchor.
e448
M. G. SAPER AND D. A. SHNEIDER
have been promising. In all cases the patella was stable with no residual medial subluxation after an average of 1 year of follow-up. There have been no cases of patellar fracture, quadriceps tendon rupture, or infection. Outcome studies are in progress.
References
Fig 6. Postoperative arthroscopic image of the patellofemoral articulation, viewed from the lateral portal (left knee), showing a stable patella, centered in the trochlea.
however, they noted patellar fractures in 3 of 60 patients that required open reduction and internal fixation. Our technique of LPFL reconstruction makes use of a quadriceps tendon graft in a fashion similar to that described by Steensen et al.15 As in their technique, the graft is detached proximally but remains attached distally so that the surgeon is required to free and secure only 1 side. The technique preserves the insertion of the graft on the patella near the normal patellar attachment of the LPFL. This enables the reconstructed ligament to function isometrically so that it will be effective through the greatest range of motion. The technique also avoids a patellar bone block and does not require drill holes through the patella, thereby eliminating the risks of patellar fracture and damage to the articular surface. The results of the medial patellofemoral ligament technique of Steensen et al.16 were promising, with good or excellent results achieved in 100% of patients and with no episodes of patellar dislocation at a mean of 42 months postoperatively. In summary, there are a limited number of reported cases of isolated MPS. This type of patellar instability might not be as rare as previously thought. It can be a subtle problem, often overlooked, and difficult to diagnose. A high index of suspicion is needed for appropriate diagnosis and treatment. LPFL reconstruction with a quadriceps tendon graft is a simple procedure with little associated morbidity. The technique is effective in preventing further episodes of instability and improving quality of life. A clear advantage of using the quadriceps tendon is the avoidance of bone tunnels, screws, and anchors in the patella, thereby avoiding the risk of patellar fracture. The senior author has performed the described technique in 3 patients with isolated MPS. Early results
1. Kramers-de Quervain IA, Biedert R, Stüssi E. Quantitative gait analysis in patients with medial patellar instability following lateral retinacular release. Knee Surg Sports Traumatol Arthrosc 1997;5:95-101. 2. Sanchis-Alfonso V, Torga-Spak R, Cortes A. Gait pattern normalization after lateral retinaculum reconstruction for iatrogenic medial patellar instability. Knee 2007;14: 484-488. 3. Abhaykumar S, Craig DM. Fascia lata sling reconstruction for recurrent medial dislocation of the patella. Knee 1999;6:55-57. 4. Hughston JC, Deese M. Medial subluxation of the patella as a complication of lateral retinacular release. Am J Sports Med 1988;16:383-388. 5. Hughston JC, Flandry F, Brinker MR, Terry GC, Mills JC III. Surgical correction of medial subluxation of the patella. Am J Sports Med 1996;24:486-491. 6. Johnson DP, Wakeley C. Reconstruction of the lateral patellar retinaculum following lateral release: A case report. Knee Surg Sports Traumatol Arthrosc 2002;10:361-363. 7. Nonweiler DE, DeLee JC. The diagnosis and treatment of medial subluxation of the patella after lateral retinacular release. Am J Sports Med 1994;22:680-686. 8. Teitge RA, Torga Spak RT. Lateral patellofemoral ligament reconstruction. Arthroscopy 2004;20:998-1002. 9. Udagawa K, Niki Y, Matsumoto H, et al. Lateral patellar retinaculum reconstruction for medial patellar instability following lateral retinacular release: A case report. Knee 2014;21:336-339. 10. Richman NM, Scheller AD Jr. Medial subluxation of the patella without previous lateral retinacular release. Orthopedics 1998;21:810-813. 11. Shannon BD, Keene JS. Results of arthroscopic medial retinacular release for treatment of medial subluxation of the patella. Am J Sports Med 2007;35:1180-1187. 12. Shellock FG, Mink JH, Deutsch A, Fox JM, Ferkel RD. Evaluation of patients with persistent symptoms after lateral retinacular release by kinematic magnetic resonance imaging of the patellofemoral joint. Arthroscopy 1990;6:226-234. 13. Waligora AC, Johanson NA, Hirsch BE. Clinical anatomy of the quadriceps femoris and extensor apparatus of the knee. Clin Orthop Relat Res 2009;467:3297-3306. 14. Navarro MS, Navarro RD, Akita Junior J, Cohen M. Anatomical study of the lateral patellofemoral ligament in cadaver knees. Rev Bras Ortop 2008;43:300-307. 15. Steensen RN, Dopirak RM, Maurus PB. A simple technique for reconstruction of the medial patellofemoral ligament using a quadriceps tendon graft. Arthroscopy 2005;21:365-370. 16. Dopirak R, Adamany D, Bickel B, Steensen R. Reconstruction of the medial patellofemoral ligament using a quadriceps tendon graft: A case series. Orthopedics 2008;31:217.
