Combined medial patellofemoral ligament and medial quadriceps tendon-femoral ligament reconstruction for patellar instability: a systematic review.

Background:Several surgical options exist for treatment of recurrent patellar instability. The treatments can be divided into ligamentous and bony procedures. It is currently unclear which patients require a bony procedure in addition to a soft tissue reconstruction.Purpose:To report the one and two-year outcomes of patients following medial patellofemoral ligament (MPFL) reconstruction performed in isolation regardless of the patellar height, tibial tubercle trochlear groove distance (TT-TG) or trochlear dysplasia.Hypothesis::Patients will have <5% re-dislocation rate and significant improvements in patient reported outcome measures (PROMs) following isolated MPFL reconstruction.Methods:All patients with recurrent patellar instability and without significant unloadable chondral defects, failed previous surgery or pain greater than or equal to 50% as their chief complaint, were prospectively enrolled beginning March of 2014. All patients underwent a primary, unilateral, isolated MPFL reconstruction regardless of concomitant bony pathology for treatment of recurrent patellar instability. Patients were followed at standard intervals. PROMs were collected at one year and two year follow up visits. Information on recurrent subjective instability, dislocations, and ability to return to sport (RTS) was recorded. TT-TG and patellar height (using the Caton-Deschamps index) were measured on magnetic resonance images.Results:Overall, 90 patients (77% female; average age 19.4 +/- 5.6 years) underwent a MPFL reconstruction from March 2014 to August 2017; 63 (70%) of whom reached one year follow up, and 35 of these patients (39%) reached 2-year follow-up. No patient experienced a redislocation; 96% of patients at one year and 100% of patients at two years had no subjective patellofemoral instability. RTS rates at one and two years were 59% and 75% respectively. No patient experienced a complication at one year. All patients had a clinically and statistically significant improvement from baseline to 1-year follow-up in the following PROMs: Knee injury and Osteoarthritis Outcome Score Quality of Life (KOOS QOL) (32.7 to 72.0; p<0.001), International Knee Documentation Committee (IKDC) (51.4 to 82.6; p<0.001) Kujala (62.2 to 89.5; p<0.001), and all general health PROM. No clinically and statistically significant change was seen between 1- and 2-year follow-ups in all outcome scores (all p>0.05). A non-statistically significant increase was seen in sporting activity of the Pediatric Functional Activity Brief Scale (Pedi-FABS) (13.9 to 16.7 p=0.292) at 2 years. Average patient satisfaction was 9.3 of 10 (10 being most satisfied) at 1- and 2-year follow-up. Average TT-TG was 15.1 +/- 4.0. Average patellar height was 1.25 +/- 0.17.Conclusion:Isolated MPFL reconstruction is an effective treatment for patellar instability and provides significant improvements in PROMs with a low redislocation/instability rate at early 1 and 2 year follow up, regardless of bony pathologies including TT-TG, Caton-Deschamps Index and trochlear dysplasia. The goal of this ongoing prospective study is to follow these patients out for 5 to 10 years to assess what radiologic and physical examination factors predict failure of isolated MPFL reconstruction.

Background: It is unclear which patients with recurrent patellar instability require a bony procedure in addition to medial patellofemoral ligament (MPFL) reconstruction. Purpose: To report 1- and 2-year outcomes of patients after isolated MPFL reconstruction performed for patellar instability regardless of patellar height, tibial tubercle–trochlear groove (TT-TG) distance, or trochlear dysplasia. Study Design: Case series; Level of evidence, 4. Methods: All patients with recurrent patellar instability and without significant unloadable chondral defects (Outerbridge grade IV), cartilage defects (especially inferior/lateral patella), previous failed surgery, or pain >50% as their chief complaint were prospectively enrolled beginning March 2014. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of concomitant bony pathology for treatment of recurrent patellar instability. Information on recurrent subjective instability, dislocations, ability to return to sport (RTS), and outcome scores was recorded at 1 and 2 years. TT-TG distance, patellar height (with the Caton-Deschamps index), and trochlear depth were measured. Results: Ninety patients (77% female; mean ± SD age, 19.4 ± 5.6 years) underwent MPFL reconstruction between March 2014 and August 2017: 72 (80%) reached 1-year follow-up, and 47 (52.2%) reached 2-year follow-up (mean follow-up, 2.2 years). Mean TT-TG distance was 14.7 ± 5.4 mm (range, –2.2 to 26.8 mm); mean patellar height, 1.2 ± 0.11 mm (range, 0.89-1.45 mm); and mean trochlear depth, 1.8 ± 1.4 mm (range, 0.05-6.85 mm). Ninety-six percent of patients at 1 year and 100% at 2 years had no self-reported patellofemoral instability; 1 patient experienced a redislocation at 3.5 years. RTS rates at 1 and 2 years were 90% and 88%, respectively. Mean time to RTS was 8.8 months. All patients had clinically and statistically significant improvement in mean Knee injury and Osteoarthritis Outcome Score–Quality of Life (32.7 to 72.0, P < .001), mean International Knee Documentation Committee subjective form (51.4 to 82.6, P < .001), and mean Kujala score (62.2 to 89.5, P < .001). No difference existed between 1- and 2-year outcome scores (all P > .05). Conclusion: At early follow-up of 1 and 2 years, isolated MPFL reconstruction is an effective treatment for patellar instability and provides significant improvements in outcome scores with a low redislocation/instability rate regardless of bony pathologies, including TT-TG distance, Caton-Deschamps index, and trochlear dysplasia. Future data from this cohort will be used to assess long-term outcomes.

Background:The most common modern procedure for medial patellar stabilization involves reconstruction of the medial patellofemoral ligament (MPFL) and involves reconstructed ligament attachment to the femur and patella. However, cases of patellar fracture have been reported, particularly in the smaller anatomy of the pediatric population, leading to further investigations of patella stabilizing structures. The medial quadriceps tendon femoral ligament has been identified as a separate structure, connecting the patella to the femur and playing a significant role in patella stability. Reconstruction of this ligament may serve a role in patellar stabilization similar to pedicled quadriceps tendon medial ligamentous reconstructions. The anatomy and relationship of the MQTFL attachment to the quadriceps tendon and proximal pole of the patella has not been described in pediatric specimens.Purpose:To determine the anatomical relationship and attachment of the medial quadriceps tendon femoral ligament (MQTFL) on the patella and quadriceps tendon.Methods:Six pediatric cadaveric knee specimens were dissected to identify the patellar and quadriceps attachment site of the MQTFL. Dissection was facilitated by lateral arthrotomy and identification of the MQTFL thickened fibers from the undersurface of the ligament.Results:Six specimens included patients a mean age of 6 years at time of patient death (three 10-year-old specimens, one 4-year-old, and one 2-month-old specimen). The MQTFL was identified in all specimens. As identified from the undersurface of the everted extensor mechanism, it was found to insert a mean distance of 10.5 mm (range 3.9 – 18.2) from the superior pole of the patella. The attachment distally along the edge of the bony patella measured a mean of 12.7 mm (range 5.4-19.4). Total patellar length, as measured from the posterior articular surface, was a mean of 24.5 mm (range 11.0-35.6). Attachment to the quadriceps tendon averaged 47% of total attachment to both the quadriceps tendon and patella; conversely, direct patellar measurement averaged 53%.Conclusion:This study provides quantitative anatomy to attachment of the MQTFL to the patella and quadriceps tendon. Precise knowledge of these structures will assist to more precisely define the complex relationship between stabilizing structures to the medial patellofemoral joint and assist in patella stabilization procedures, particularly in skeletally immature patients. A lower risk of patellar fracture may be one of the key benefits of this procedure, compared with MPFL reconstruction.FIGURESFigure 1:.View from the posterior surface (ie inside joint) following lateral arthrotomy. Note MQTFL attachment point in relation to the proximal extent of the cartilaginous articular surface.ReferencesFulkerson JP, Edgar C. Medial quadriceps tendon-femoral ligament: Surgical anatomy and reconstruction technique to prevent patella instability. Arthrosc Tech 2013;2:e125- e128.Joseph SM, Fulkerson JP. Medial Quadriceps Tendon Femoral Ligament Reconstruction Technique and Surgical Anatomy. Arthroscopy techniques. 2019 Jan 1;8(1):e57-64.Parikh SN, Wall EJ. Patellar fracture after medial patel- lofemoral ligament surgery: A report of five cases. J Bone Joint Surg Am 2011;93. e97(1-8)Dhinsa BS, Bhamra JS, James C, Dunnet W, Zahn H. Patella fracture after medial patellofemoral ligament reconstruction using suture anchors. Knee 2013;20:605- 608.Shah JN, Howard JS, Flanigan DC, Brophy RH, Carey JL, Lattermann C. A systematic review of complications and failures associated with medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Am J Sports Med 2012;40:1916-1923Tanaka MJ. The anatomy of the medial patellofemoral complex. Sports Med Arthrosc 2017;25:e8-e11.Kruckeberg BM, Chahla J, Moatshe G, et al. Quantitative and qualitative analysis of the medial patellar ligaments: An anatomic and radiographic study. Am J Sports Med 2017. 363546517729818LaPrade RF, Engebretsen AH, Ly TV, Johansen S, Wentorf FA, Engebretsen L. The anatomy of the medial part of the knee. J Bone Joint Surg Am 2007;89:2000- 2010.Mochizuki T, Nimura A, Tateishi T, Yamaguchi K, Muneta T, Akita K. Anatomic study of the attachment of the medial patellofemoral ligament and its characteristic relationships to the vastus intermedius. Knee Surg Sports Traumatol Arthrosc 2013;21:305-310.Nelitz M, Williams SR. Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft. Arthroscopy techniques. 2014 Apr 1;3(2):e303-8.

Background: Medial patellofemoral ligament (MPFL) reconstruction has become one of the most common and widely used procedures to regain stability among patients with recurrent lateral patellar dislocation. While recent studies demonstrated low recurrence rates, improved patient-reported outcome measures, and a high rate of return to sports, limited literature explored its effectiveness as an isolated intervention in the context of trochlear dysplasia. Purpose: To determine the efficacy of isolated MPFL reconstruction in treating patellar instability in the setting of trochlear dysplasia. Study Design: Case series; Level of evidence, 4. Methods: This was a retrospective review of consecutive patients who underwent uni- or bilateral medial patellofemoral ligament reconstruction for patellofemoral instability with a minimum 2-year follow-up. No osteotomies were included. Pre- and postoperative assessment included ligamentous laxity, patellar crepitus, tilt, translation, apprehension, and radiographic features, including tibial tubercle-trochlear groove (TT-TG) distance, Dejour classification, and Caton-Deschamps index. Results: A total of 121 MPFL reconstructions were included. Mean age at surgery was 23.8 years, and 4.4 dislocation events occurred before surgery. Mean follow-up was 44 months; 76% of patients were female. Mean preoperative TT-TG ratio was 13.5, and mean Caton-Deschamps ratio was 1.2; 92% of patients had Dejour B, C, or D trochlear dysplasia. Kujala score improved from 55.0 preoperatively to 90.0 (P < .001). Almost all patients (94.5%) were able to return to sports at 1 year, with 74% returning to the same or higher level of play. Only 3 patients reported a postoperative dislocation or subluxation event. Discussion: For patients without significantly elevated TT-TG distances or significant patella alta, isolated MPFL reconstruction provides a safe and effective treatment for patellofemoral instability, despite the presence of trochlear dysplasia. Most patients are able to return to sports by 1 year postoperatively at the same or higher level of play.

Background: There is a lack of evidence regarding the optimum extensor-sided fixation method for medial patellofemoral ligament (MPFL) reconstruction. There is increased interest in avoiding patellar drilling via soft tissue–only fixation to the distal quadriceps, thus reconstructing the medial quadriceps tendon–femoral ligament (MQTFL). The biomechanical implications of differing extensor-sided fixation constructs remain unknown. Hypothesis: The null hypothesis was there would be no differences between traditional MPFL reconstruction and MQTFL reconstruction with respect to resistance to lateral translation, patellar position, or patellofemoral contact pressures. Study Design: Controlled laboratory study. Methods: Nine adult knee specimens were mounted on a jig that applied static, physiologic loads to the quadriceps tendons. Patellar position and orientation, knee flexion angle, and patellofemoral pressure were recorded at 8 different flexion angles between 0° and 110°. Additionally, a lateral patellar excursion test was conducted wherein a load was applied directly to the patella in the lateral direction with the knee at 30° of flexion and subjected to 2-N quadriceps loads. Testing was conducted under 4 conditions: intact, transected MPFL, MQTFL reconstruction, and MPFL reconstruction. For MQTFL reconstruction, the surgical technique established by Fulkerson was employed. For MPFL reconstruction, a traditional technique was utilized. Results: The patellar excursion test showed no significant difference between the MQTFL and intact states with respect to lateral translation. MPFL reconstruction led to significantly less lateral translation (P < .05) than all other states. There were no significant differences between MPFL and MQTFL reconstructions with respect to peak patellofemoral contact pressure. MPFL and MQTFL reconstructions both resulted in increased internal rotation of the patella with the knee in full extension. Conclusion: Soft tissue-only extensor-sided fixation to the distal quadriceps (MQTFL) during patella stabilization appears to re-create native stability in this time 0 cadaver model. Fixation to the patella (MPFL) was associated with increased resistance to lateral translation. Clinical Relevance: Evolving anatomic knowledge and concern for patellar fracture has led to increased interest in MQTFL reconstruction. Both MQTFL and MPFL reconstructions restored patellofemoral stability to lateral translation without increasing contact pressures under appropriate graft tensioning, with MQTFL more closely restoring native resistance to lateral translation at the time of surgery.

PurposeThis study aimed to highlight short- and medium-term outcomes of combined medial patello-femoral ligament (MPFL) reconstruction and anterior tibial tuberosity (ATT) transposition surgery in patients with recurrent patellar instability and different degrees of trochlear dysplasia.MethodsBetween January 2014 and May 2019, 25 patients with patellar instability underwent a surgical procedure combining the lowering/transposition of the ATT and the MPFL reconstruction. Each patient were preoperative assessed by Kujala score, International Knee Documentation Committee (IKDC), Tegner activity level scale. The assessment of instability predisposing factors was carried out with patellar height, tibial tuberosity-trochlear groove (TT-TG) distance, trochlear dysplasia, sulcus angle, patellar tilt and MPFL injuries. Functional outcomes were evaluated with Kujala, IKDC and Tegner scores at 3, 6 and 12 months after surgery.ResultsThe average age of the patients was 20 years (range 13–43 years). Pre- operative Caton–Deschamps index was pathological in 10 (40%). Sulcus angle was elevated in 13 patients (52%) and TT-TG distance was irregular in 17 patients (68%). Trochlear dysplasia was present in 13 patients (9 type A, 3 type B, 1 type C according to Dejour’s Classification). No re-dislocation occurred during the follow-up. There was a significant increase in the Kujala, IKDC and Lysholm scores after 3, 6 and 12 months, and the results were compared for the different follow-up times and patient’s trochlear dysplasia degree.ConclusionThis prospective observational longitudinal study identified good clinical outcomes in patients who underwent MPFL reconstruction and ATT transposition for patellar instability. Finally, the different risk factors for patellar instability examined, particularly the presence of trochlear dysplasia, did not significantly influence the final functional results, which range from good to excellent without re-dislocation episodes.

Objectives:A variety of surgical options exist to treat the challenging problem of recurrent patellar instability in skeletally immature patients. The current study describes a combined reconstruction technique involving both the medial patellofemoral ligament (MPFL) and the medial quadriceps tendon - femoral ligament (MQTFL) and reports patient outcomes of a single-surgeon series.Methods:All patients studied underwent combined MPFL and MQTFL reconstruction for patellar instability. Demographic data, pre- and post-operative radiographic data were collected. Reconstruction was performed using gracilis allograft. The graft midportion was fixed to the MPFL insertion on the femur via suture anchor. One arm of the graft (MPFL) was tunneled under medial retinaculum to the medial border of the patella and fixed there via suture anchor, while the other (MQTFL) arm was tunneled, delivered under the VMO and brought through the medial distal quadriceps tendon and sutured in place. Subjective outcome scores (Kujala, Pedi-IKDC, Lysholm) were collected via questionnaires mailed to patients more than one year from surgery.Results:A total of 25 patients (27 knees), including 15 females and 10 males with an average age of 15.0 ± 2.2 years (range 10.3-18.9), underwent combined MPFL and MQTFL reconstruction. 6/25 (24%) had undergone prior ipsilateral patellofemoral surgery for instability. 5/25 (20%) underwent simultaneous guided growth via hemiepiphysiodesis for valgus deformity at the time of combined reconstruction. Preoperative imaging showed a mean TT-TG of 17.2 ± 3.8, Caton-Deschamps Index (CDI) of 1.13 ± 0.16, and trochlear dysplasia Dejour A/B (22/26 (85%)) or Dejour C/D (4/26 (15%)). A total of 18 patients (19 knees, 72%) returned outcomes questionnaires at a mean 2.0 ± 0.5 years after surgery. Mean Kujala, Pedi-IKDC, and Lysholm scores were 85.9 ± 13.9, 81.5 ± 15.2, and 84.3 ± 13.5, respectively. 2/25 patients (8%) later required a revision procedure (tibial tubercle osteotomy) for recurrent patellar instability, and another patient reported persistent instability not requiring revision. 10/13 patients (77%) were able to return to sports at a mean of 5.8 +/- 3.9 months (range 2-15).Conclusion:The current study describes a novel anatomically-validated surgical technique involving the simultaneous reconstruction of both the MPFL and MQTFL in a pediatric patient population. Follow-up data presented demonstrates overall positive results in treating this challenging problem in a young patient population.

Patellofemoral instability is due to a combination of bony and soft tissue factors. While recurrent patellar dislocations are rare, evaluation and treatment of these conditions require addressing patellar height and lateralization of the tibial tubercle (TT), restraint to lateral patellar subluxation, and trochlear dysplasia. Other factors to consider are coronal limb-length alignment outside of the physiologic 5 to 8° of valgus, which may significantly alter the Q angle and contribute to lateral instability. Other ligaments around the patella contribute to soft-tissue restraint, including the medial and lateral patellotibial ligaments, patellomeniscal ligaments, and the medial quadriceps tendon femoral ligament. Patellar tilt is assessed with and without quadriceps contraction to further evaluate the patella's relationship to the trochlear groove. The Caton-Deschamps Index, as well as patellar trochlear index (PTI), are used to measure patellar height for patella alta or baja. The technique is to surgically manage a patient in neutral mechanical alignment on standing limb radiographs, with moderate-to-severe DeJour type B trochlear dysplasia and a trochlear sulcus angle of around 145°, patella alta with a Caton-Deschamps Index of 1.6 and PTI of 0.22, a TT to trochlear groove (TT-TG) distance of 8 mm, and a deficient medial patellofemoral ligament (MPFL). The MPFL reconstruction is done first, with harvesting of the ipsilateral quadriceps tendon and maintenance of its distal attachment on the superior patellar pole. The quadriceps tendon graft is folded medially upon its distal attachment and fixed in this position with suture anchors. Tibial tubercle osteotomy is accomplished by spacing drill holes 2 mm apart, medially and laterally, on the TT and connecting the drill holes with an osteotome and reciprocating saw. A distalized location to secure the TT is selected and superficial bone is excised. A medial parapatellar arthrotomy is performed, and bur attachments are used to drill into the subchondral bone beneath the femoral articular surface to create a V-shaped flap of trochlear cartilage. An arthroscope is inserted under the trochlear flap during this process to visualize the appropriate depth. The trochlear flap is then secured with screws passed over guide pins to secure the flap to the desired location. Cannulated screws and washers are then used to secure the TT to its distalized and/or medialized position, with fluoroscopic verification of screw depth and location. The arthrotomy is then closed with the knee at 45°. The quadriceps graft is passed through a subretinacular channel and secured with suture anchors, adjacent to the adductor tubercle, to complete the MPFL reconstruction. Before closure, appropriate tracking and translation of the patella is verified. Sulcus-deepening trochleoplasty, with or without MPFL reconstruction, has been reported to obtain satisfactory outcomes at 2 years, with close to 85% return to sport and 100% return to work, with improvements in International Knee Documentation Committee (IKDC) scores from 50.8 to 79.1 in some studies. MPFL reconstruction with tibial tubercle osteotomy (TTO) has yielded a 94.5% patient satisfaction rate in the literature. In patients with recurrent patellar instability and DeJour types B-D trochlear dysplasia, MPFL reconstruction with TTO and sulcus-deepening trochleoplasty provides excellent subjective outcomes and restores patellar tracking with elimination of recurrent subluxation.

Allograft Medial Patellofemoral Ligament Reconstruction in Adolescent Patients Results in a Low Recurrence Rate of Patellar Dislocation or Subluxation at Midterm Follow-Up

Biomechanical Comparison of 3 Medial Patellofemoral Complex Reconstruction Techniques Shows Medial Overconstraint but No Significant Difference in Patella Lateralization and Contact Pressure

CORR Synthesis: Can Guided Growth for Angular Deformity Correction Be Applied to Management of Pediatric Patellofemoral Instability?

Patellar dislocation is a common knee injury and up to 35% of those who dislocate the patella can develop recurrent patellar instability. In the setting of recurrent instability, medial patellofemoral ligament (MPFL) reconstruction is often performed to restore knee stability. There has been recent interest in patient and surgical factors that influence outcomes of MPFL reconstruction. Much of the previous work has focused on influences of anatomic measures; however, patients and injury characteristics may also impact surgical outcomes. Patients who experience >2 patellar dislocations before MPFL reconstruction would demonstrate poorer patient-reported outcomes (PROs) compared with those with ≤2 previous dislocations. Cohort study; Level of evidence, 3. Records were reviewed to identify patients who underwent MPFL reconstruction at a single institution between 2008 and 2016. Patients who underwent concomitant tibial tubercle osteotomy or fixation of an osteochondral fracture were excluded. Patient demographics (age, sex, body mass index [BMI]), number of previous patellar dislocations, and patient anatomic measures (Caton-Deschamps index (CDI), tibial tubercle-trochlear groove (TT-TG) distance, and trochlear sulcus angle) were collected. PROs were assessed with Norwich Patellar Instability score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Marx activity score. Outcomes of patients with >2 patellar dislocations were compared with those with ≤2 dislocations using multiple linear regression analysis. Medical record review revealed 160 patients who underwent isolated MPFL reconstruction (71 with ≥2 dislocations and 89 with >2 dislocations); 95 patients (59%) completed PROs at a median follow-up of 4.6 years postoperation (range, 1.0-12.6 years). Patients with ≥2 dislocations were younger (≥2 dislocations: 20.7 ± 7.3 years, >2 dislocations: 28.5 ± 10.0 years; P < .001), although there were no other differences in demographics or radiographic anatomic measures between groups. Adjusting for age, sex, BMI, CDI, TT-TG distance, and trochlear sulcus angle, patients with >2 dislocations had 13.7 points lower KOOS-Pain (P = .003), 8.3 points lower KOOS-Activities of Daily Living (P = .025), 18.2 points lower KOOS-Sports and Recreation (P = .009), and 19.8 points lower KOOS-Knee-Related Quality of Life (P = .008) subscale scores than patients with ≤2 dislocations. No significant differences in KOOS symptoms subscale, Norwich Patellar Instability, or Marx score were noted between groups. Patients with >2 patellar dislocations before MPFL reconstruction exhibited poorer PROs at a median of 4.8 years postoperation compared with those who had ≤2 dislocations before surgery, when adjusting for age, sex, BMI, CDI, TT-TG distance, and trochlear sulcus angle.

Clinical Outcomes after Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability with Trochlear Dysplasia

A variety of surgical options exist to treat the challenging problem of recurrent patellar instability in children and adolescents. The goal of the current study is to describe a novel combined reconstruction technique of both the medial patellofemoral ligament (MPFL) and the medial quadriceps tendon-femoral ligament (MQTFL) and report patient outcomes of a single-surgeon series. All patients studied underwent simultaneous MPFL and MQTFL reconstruction for patellar instability using gracilis allograft. Demographic, clinical, and radiographic data were collected. Subjective outcomes were assessed for a minimum of 1 year postoperatively. Twenty-five patients (27 knees), including 15 female and 10 male individuals with an average age of 15.0±2.2 years (range, 10.3 to 18.9), were included. Prior ipsilateral patellofemoral surgery had been performed in 6 of 25 (24%) patients. Simultaneous hemiepiphysiodesis for valgus deformity at the time of combined reconstruction was performed in 5 of 25 (20%) patients. Preoperative imaging showed a mean tibial tubercle-trochlear groove of 17.2±3.8, Caton-Deschamps Index (CDI) of 1.13±0.16, and trochlear dysplasia Dejour A/B [22/26 (85%)] or Dejour C/D [4/26 (15%)]. A total of 18 patients (19 knees, 72%) returned outcomes questionnaires at a mean 2.0±0.5 years after surgery. Mean Kujala, Pedi-IKDC, and Lysholm scores were 85.9±13.9, 81.5±15.2, and 84.3±13.5, respectively. Later revision procedure (tibial tubercle osteotomy) for recurrent patellar instability was required in 2 of 25 patients (8%) patients, and another patient reported persistent instability not requiring revision. Return to sports was possible in 10 of 13 self-reported athletes (77%) at a mean of 5.8±3.9 months (range, 2 to 15). The present study describes a combined MPFL-MQTFL reconstruction technique with favorable short-term results. Although particularly useful in the skeletally immature patient where tibial tubercle osteotomy should be avoided and patellar fixation minimized, combined reconstruction may potentially be appropriate for older patients with patellofemoral instability as well. This technique more closely recreates the native anatomy of both the MPFL and MQTFL, may decrease the risk of patellar fracture, and can be useful in the revision setting. Level IV.

Hypermobility is an acknowledged risk factor for patellar instability. In this case control study the influence of hypermobility on clinical outcome following medial patellofemoral ligament (MPFL) reconstruction for patellar instability was studied. A total of 25 patients with hypermobility as determined by the Beighton criteria were assessed and compared with a control group of 50 patients who were matched for age, gender, indication for surgery and degree of trochlear dysplasia. The patients with hypermobility had a Beighton Score of ≥ 6; the control patients had a score of < 4. All patients underwent MPFL reconstruction performed using semitendinosus autograft and a standardised arthroscopically controlled technique. The mean age of the patients was 25years (17 to 49) and the mean follow-up was 15 months (6 to 30). Patients with hypermobility had a significant improvement in function following surgery, with reasonable rates of satisfaction, perceived improvement, willingness to repeat and likelihood of recommendation. Functional improvements were significantly less than in control patients (p < 0.01). Joint hypermobility is not a contraindication to MPFL reconstruction although caution is recommended in managing the expectations of patients with hypermobility before consideration of surgery.