Treatment Of Recurrent Patellar Instability Research Articles

Evaluation of the Results of Reconstruction of Medial Patellofemoral Ligament in the Treatment of Recurrent Patellar Instability Using Hamstring Autograft by Dual Patella Docking Technique

Abstract Background: Recurrent patellar instability can significantly affect a patient’s life quality. This study evaluated the results of medial patellofemoral ligament (MPFL) reconstruction in the recurrent patellar instability treatment using hamstring autograft by dual patellar docking technique. Materials and Methods: This prospective study was performed on 20 recurrent patellar instability patients. Magnetic resonance imaging and computed tomography scans were performed to confirm MPFL tear and assess the tibial tubercle-trochlear groove distance. Various clinical and radiographic evaluations were performed preoperatively. The surgical technique involved diagnostic arthroscopy, graft preparation, patellar preparation, graft passage, femoral tunnel preparation, and graft fixation. Results: Postoperatively, a substantial progression was observed in the International Knee Documentation Committee score, Kujala score, Cincinnati score, and Lysholm score compared to preoperative values (P < 0.001). In addition, the postoperative measurements of patellar tilt angle and patellar congruence angle were significantly lower than their respective preoperative values (P < 0.001). All 20 (100%) patients had negative findings in the postapprehension test, indicating improved stability. In the postcompression test, 3 (15%) patients showed positive results, whereas 17 (85%) patients had negative results. In terms of complications, 2 (10%) patients experienced patellofemoral pain, 1 (5%) patient had residual patellar translation without dislocation, 1 (5%) patient had limited flexion, and the majority of patients (16, 80%) had no complications. Conclusions: MPFL reconstruction with patellar docking yielded good results with Kujala and Lysholm, as well as adequate, satisfactory congruence angles for most patients. This procedure has exhibited a high success rate in addressing patellofemoral instability.

C-Arm Guidance During Thin Flap Arthroscopic Trochleoplasty for Chronic Patellar Instability

The purpose of this paper is to provide a complete Technical Note for our treatment of choice for recurrent patellar dislocation in cases of trochlear dysplasia, especially in patients with types B and D trochlear dysplasia according to the Dejour classification. Different surgical procedures have been reported for the treatment of recurrent patellar instability. One of the most important anatomic factors to address when treating a recurrent patella dislocation is trochlear dysplasia. Few types of open trochleoplasty have been classically described to treat a dysplastic trochlea. However, in recent years, arthroscopic techniques have been reported to reduce invasiveness and complications as well as to improve accuracy and clinical outcomes. In this technique is described an arthroscopic thin-flap tracheoplasty with the use of C-arm guidance in order to precisely control the bone resection and to verify intraoperatively the disappearance of the radiologic landmarks used for diagnosis and classification of the dysplasia. The advantage of this technique is the precision in removal of the supratrochlear spur and bump, the accurate and delicate reshaping of the sulcus with preservation of cartilage vitality, combined with increased reproducibility and safety.

Reconstruction of Medial Patellofemoral Ligament in the Treatment of Recurrent Patellar Instability using Hamstring Autograft by Dual Patella Docking Technique: A Comparative Review

Reconstruction of Medial Patellofemoral Ligament in the Treatment of Recurrent Patellar Instability using Hamstring Autograft by Dual Patella Docking Technique: A Comparative Review

High incidence of complication following tibial tubercle surgery

ObjectivesTibial tubercle osteotomy (TTO) is a common procedure that is frequently used in the treatment of recurrent patellar instability and/or patellar chondrosis. Current estimates of TTO complications in the literature vary widely, with complication rates reaching 59 percent. This variability is due, in part, to inconsistent definitions of complication between studies. The purpose of this study was to identify our complication rate following TTO procedures, with sub-analysis of whether the complication rate was affected by:1. An intra-articular component defined as an additional procedure that altered post-operative rehabilitation and2. A distalization of the tubercle translation. MethodsAll patients between May 2009 and May 2015 who underwent a TTO were retrospectively identified. Complications were defined as major (fracture of the tibia, deep infection, non-union, delayed union, arthrofibrosis, deep vein thrombosis (DVT) and loss of screw fixation) versus minor (superficial wound infection, disturbance of cutaneous sensation and delay in wound healing). Subgroup analysis of distalization versus no distalization and intra-versus extra-articular concomitant procedures were also analysed. ResultsOne hundred and sixty-three TTOs in 150 patients were included in the final cohort with a mean follow-up of 21.3 months. The overall complication rate was 35 major complications (21.5%) and 13 minor complications (8.0%), with a total complication rate of 29.5 percent. TTO distalization did not increase the rate of complications. DVT was only seen in the intra-articular procedure cohort (n = 3/1.8%). Arthrofibrosis was the most common complication, occurring in 17 knees. ConclusionThe overall complication rate of TTOs was 29.5%, with arthrofibrosis (10.4%) as the largest complication. DVT increased with concomitant intra-articular procedure. Distalization of the tubercle compared to no distalization had no significant effect on complications. Level of evidenceRetrospective Cohort study, level III.

Combined MPFL Reconstruction with Tibial Tubercle Osteotomy and Repair of Patellar Cartilage Defect with Particulated Juvenile Articular Cartilage.

Combined MPFL Reconstruction with Tibial Tubercle Osteotomy and Repair of Patellar Cartilage Defect with Particulated Juvenile Articular Cartilage.

Paper 50: Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Regardless of Tibial Tubercle - Trochlear Groove Distance and Patellar Height: Minimum 5-Year Outcomes

Objectives:It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction. The purpose of this study is to provide midterm results on previously reported patient reported outcomes (PRO), return to sport (RTS) and imaging measurements collected for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial. This includes minimum 5-year outcomes data on a cohort of 55 patients as well as 2-year outcomes data on an expanded cohort of 121 patients.Methods:Patients with recurrent patellar instability who did not meet exclusion criteria were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included patients with a prior history of a patellar stabilization procedure, an off-loadable (inferior/lateral) Outerbridge Grade IV chondral defect, obligatory dislocators (patients who require patellar dislocation in order to achieve full knee extension) or patients with a “Jumping J” sign and patients who reported anterior knee pain as more than 50% of their chief complaint.All patients who were not excluded by the above criteria underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomy (tibial tubercle - trochlear groove (TT-TG), trochlear morphology, trochlear depth, or patellar height) for treatment of recurrent patellar instability. Patient data including PROs, episodes of recurrent instability or dislocation, and ability to return to sport (RTS) was obtained annually. Radiographic MRI measurements including TT-TG, Caton-Deschamps Index (CDI), Patellar Trochlear Index (PTI), Trochlear Depth Index (TDI), Patellar Tendon to Lateral Trochlear Ridge (PT-LTR) and Tibial Tubercle to Lateral Trochlear Ridge (TT-LTR) were obtained at baseline.Results:138 patients (72% female; mean age 20.1 ± 6.1 years) underwent isolated MPFL reconstruction between March 2014 and December 2019. 55 patients reached the ≥5-year postoperative time point, of which 40 (72%) completed follow-up PROs. 121 patients reached the ≥2-year postoperative time point, of which 89 (74%) completed follow-up PROs.99% (n=136) of patients at 2 years and 96% (n=132) of patients at ≥ 5 years had no self-reported post-operative patellofemoral instability: 6 patients (4%) reported recurrent instability at a mean of 3.0 ± 0.7 years postoperatively. Activities during which failure occurred included jumping on a trampoline, dancing, and playing lacrosse.Preoperatively, 100 (72%) patients participated in sports or physical activity, of which 87 reported return to sport (87%). All patients that returned to sport did so within 24 months postoperatively with a mean RTS of 9.3 months. KOOS-Qol, Pedi-Fabs, IKDC, KOOS-PS and Kujala PROS are reported in Table 1.The mean TT-TG was 15.1 ± 4.9 mm (1.90 to 27.2 mm), mean CDI was 1.14 ± 0.16 (0.72 to 1.65), mean PTI was 46.9 ± 15.1% (13 to 100%) and mean trochlear depth was 2.5 ± 1.2 mm (-1.55 to 5.15 mm). Trochlear dysplasia, defined as a TDI < 3 mm, was present in 77 (56%) of patients. The mean measure of extensor mechanism containment, TT-LTR, was -8.4 ± 5.7 mm (-24.0 to 3.20 mm) and the rate of TT-LTR within 1 mm, found to be predictive of recurrent instability, was 8% (n=11). The mean PT-LTR, a measurement of lateral patellar tracking, was 5.7 ± 6.2 mm (-5.70 to 21.1 mm).The six patients who experienced recurrent instability after an isolated MPFL reconstruction had a mean CDI of 1.19 and a mean TT-TG of 18.75. Individual imaging data for these six patients can be seen in Table 2.Conclusions:Midterm outcomes for patients who underwent isolated MPFL reconstruction (within strict exclusion criteria parameters) are shown to be favorable and maintained at 5 years. Additionally, the outcomes for the expanded cohort of patients with a minimum of 2-year follow up supports the previously published results. Most athletes were able to return to sport. Completion of this study enrollment with long term follow up will allow for more robust assessment of long-term outcomes and incidence of recurrent instability after isolated MPFL reconstruction. The ultimate goal of this work is the creation of a predictive model utilizing the bony and clinical characteristics of those patients who sustain recurrent instability in order to better predict who might benefit from additional bony realignment procedures at the time of their index procedure.Table 1.Patient Reported Outcomes at Baseline, 2 years and ≥ 5 yearsTable 2.Radiographic Measurements for Patients with Recurrent Patellar Instability after Isolated MPFL Reconstruction

Revision surgery for failed medial patellofemoral ligament reconstruction results in better disease-specific outcome scores when performed for recurrent instability than for patellofemoral pain or limited range of motion

Medial patellofemoral ligament reconstruction (MPFL-R) is an important treatment for recurrent patellar instability. Although complications such as redislocation, patellofemoral pain (PFP) and restricted knee range of motion have been reported, few studies have investigated the results of revision surgery for failed MPFL-R. Thus, the aim of this study was to determine the results of the tailored revision surgery after considering the cause of the reconstruction failure. Between 2015 and 2019, 28 patients (male/female 9/19; age 26.2 ± 6.4years) underwent revision surgery for failed MPFL-R. The patients were grouped into the "recurrent instability" (SG1) group and "PFP" and/or "restricted range of motion" (SG2) group. Preoperatively, the clinical data, anatomical risk factor profile, and position of the femoral MPFL tunnel were determined for each patient. The Banff Patella Instability Instrument 2.0 (BPII 2.0) and numerical analogue scale (NAS 0-10) were administered preoperatively and at the final follow-up for the subjective assessment of the PFP and knee joint function. Overall, the BPII 2.0 score improved from 28.8 ± 16.6 points preoperatively to 68.0 ± 22.7 points (p < 0.0001) postoperatively. SG1 exhibited an increase in the BPII 2.0 score from 28.9 ± 20.2 points to 75.7 ± 23 points (p < 0.0001). PFP decreased from 6.8 ± 2.4 to 1.6 ± 1.9 (p < 0.0001), while the knee joint function increased from 4.3 ± 2.5 to 8.8 ± 1.6 (p < 0.0001). In SG2, the BPII 2.0 score increased from 28.7 ± 12.6 points preoperatively to 57.7 ± 19.7 points (p = 0.0002) postoperatively and was thus significantly lower than that in SG1 (p = 0.038). The intensity of PFP decreased from 6.6 ± 3.0 preoperatively to 2.1 ± 1.9 postoperatively (p = 0.0006), while the subjective knee joint function improved from 3.2 ± 1.4 preoperatively to 7.6 ± 2.3 postoperatively (p < 0.0001). The differences between the groups were not significant. Tailored revision surgery for failed MPFL-R significantly improves the patient-reported disease-specific quality of life. The study results indicate that patients undergoing revision surgery as a consequence of patellar redislocation appear to benefit more from revision surgery than those patients undergoing revision due to postoperative PFP and/or a limited knee joint range of motion. Level IV.

Medial Patellofemoral Ligament Reconstruction Using a Quadriceps Tendon Autograft in a Patient with Open Physes

Recurrent patellar dislocations are correlated with an elevated risk for further patellar dislocations. Chronic patellar instability is a disabling issue for some patients and may require surgical intervention for proper treatment. Risk factors for recurrent dislocations include medial patellofemoral ligament (MPFL) tears, patella alta, trochlear dysplasia, and increased tibial tubercle to trochlear groove distance. Surgical management must be based on a patient’s unique joint pathoanatomy and typically requires medial patellofemoral ligament reconstruction, with or without accompanying procedures such as tibial tubercle osteotomy or sulcus-deepening trochleoplasty. Chronic patellar instability in minors with open growth plates, requires alternative MPFL reconstruction techniques to prevent physeal injury, because of the close proximity of the femoral physis to the MPFL insertion. This article discusses the authors’ preferred technique for surgical treatment of recurrent patellar instability with a medial patellofemoral ligament reconstruction using a quadriceps tendon autograft.

Medial Patellofemoral Reconstruction Using Quadriceps Tendon Autograft, Tibial Tubercle Osteotomy, and Sulcus-Deepening Trochleoplasty for Patellar Instability

Recurrent patellar dislocations have been correlated with an elevated risk of further patellar dislocations, often requiring surgical treatment. Risk factors include medial patellofemoral ligament (MPFL) tears, patella alta, trochlear dysplasia, and an increased tibial tubercle–trochlear groove distance. Surgical management must be based on a patient’s unique joint pathoanatomy and may require MPFL reconstruction with tibial tubercle osteotomy or trochleoplasty either alone or in combination. This article discusses our preferred technique for surgical treatment of recurrent patellar instability with MPFL reconstruction using a quadriceps tendon autograft, an open trochleoplasty, and a tibial tubercle osteotomy for patients with patella alta, trochlear dysplasia, and an increased tibial tubercle–trochlear groove distance.

Return to Play After Medial Patellofemoral Ligament Reconstruction: A Systematic Review

Background: Medial patellofemoral ligament (MPFL) reconstruction is being performed more frequently in athletes experiencing recurrent patellar instability. Purpose/Hypothesis: The purpose was to systematically review the evidence in the orthopaedic sports medicine literature to determine both the rate and timing of return to play after MPFL reconstruction and the rate of further patellar instability. Our hypothesis was that there would be a high rate of return to play after MPFL reconstruction. Study Design: Systematic review. Methods: A systematic literature search was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, which utilized EMBASE, MEDLINE, and the Cochrane Library databases. Inclusion criteria for literature included clinical studies reporting on return to play after MPFL reconstruction. Rate of return to play, level of return, timing of return, rate of recurrent instability, and patient-reported outcomes were evaluated. Statistical analysis was performed using SPSS. Results: Our review found 27 studies including 1278 patients meeting our inclusion criteria. The majority of patients were women (58%), and the total group had a mean age of 22.0 years and a mean follow-up of 39.3 months. The overall rate of return to play was 85.1%, with 68.3% returning to the same level of play. The average time to return to play was 7.0 months postoperatively. The rate of recurrent instability events following reconstruction was 5.4%. There was an improvement in both mean visual analog scale, pain scores (preoperative: 4.3, postoperative: 1.6) and Tegner activity scores (preoperative: 4.8, postoperative: 5.5). Conclusion: The overall rate of return to play was high after MPFL reconstruction for the treatment of recurrent patellar instability. However, a relatively high percentage of those patients were unable to return to their preoperative level of sport. Additionally, there was a moderate time taken to return to play, at approximately 7 months after the procedure.

Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability in Skeletally Immature versus Mature Patients

Objectives:Medial patellofemoral ligament (MPFL) reconstruction is the standard of care surgical treatment for recurrent patellar instability. Recurrent patellar instability is common after a first-time dislocation in the skeletally immature population. Adult-type reconstruction techniques are often avoided in skeletally immature patients due to the proximity of the femoral insertion of the MFPL to the distal femoral physis. It is currently unclear how outcomes of MPFL reconstruction in skeletally immature patients compare to those for skeletally mature patients. The objective of this study is to present the outcomes of isolated MPFL reconstruction in skeletally immature patients and compare their findings to a skeletally mature population.Methods:Patients were identified from an institutional patellofemoral registry who underwent isolated MPFL reconstruction from March 2014 to July 2018. Demographic, radiographic, and knee-specific patient-reported outcome measures (PROMs) were collected prior to surgery. Follow-up data collection included knee surveys collected at 1 and 2-years following MPFL reconstruction. Additionally, return to sport rates and episodes of re-dislocations were also collected. Comparisons of demographic and clinical data were made between skeletally immature and mature patients. Sub-analysis was performed on outcomes in skeletally immature patients who underwent MPFL reconstruction where the graft was placed distal to the physis to avoid the growth plate versus those who had standard placement of the graft. Baseline factors were analyzed using independent samples t-tests or chi-square analysis. Longitudinal analysis of knee PROMs was conducted using generalized estimating equation (GEE) modeling. Statistical significance was defined as p-values of 0.05 or less.Results:The study cohort included 107 patients (25 skeletally immature, 82 skeletally mature). Mean age of the study groups was 13.8 years in the immature group (range 11-15) and 21.3 in the mature group (range 14-34). No differences in sex (72% female in both groups) or obesity (0% vs. 8%) was observed between immature and mature patients. Radiographic measures of Caton-Deschamps Index (1.18 in both groups), TT-TG (14.9 vs. 14.8), and Dejour classification (P=0.328) also saw no differences between groups. Longitudinal outcomes in KOOS QoL, IKDC, KOOS PS, and Kujala surveys found no differences between immature versus mature patients over time. However, higher PediFABS was observed in the immature group versus mature at baseline (21.6 vs. 11.9, P<0.001), 1-year (18.1 vs. 11.5, P=0.006), and 2-years (22.4 vs. 11.5, P=0.003). Low incidence of post-operative dislocation and a high return to sport rate was observed in both skeletally immature and mature patients. No statistical differences were observed in all outcomes between immature patients who had standard graft placement and those where the graft was placed distal to the physis.Conclusion:Controversy exists in how best to treat the skeletally immature patient with recurrent lateral patellar instability. Due to the risk of injury to the growth plate, many believe it is best to wait to stabilize these patients until they have stopped growing. However, given the high risk of cartilage injury with each dislocation and the long term sequelae of such injuries in these young knees, the risk of waiting may be high. This study demonstrates similar outcomes and recurrence rates in skeletally immature patients with those seen in the mature population without disturbance or injury to the growth plates.Figure 1.Figure 2.

Sulcus Deepening Trochleoplasty and Medial Patellofemoral Ligament Reconstruction for Patellofemoral Instability: A 2-Year Study

To evaluate outcome data of patients undergoing DeJour sulcus-deepening trochleoplasty with medial patellofemoral ligament reconstruction (MPFLR) for high-grade trochlear dysplasia at a single institution in the United States. A total of 67 patients (76 knees) with severe trochlear dysplasia and recurrent patellar instability were prospectively enrolled and underwent DeJour sulcus-deepening trochleoplasty with MPFLR from 2011 to 2019. Inclusion criteria included recurrent lateral patellar instability following failure of conservative treatment with radiographic evidence of severe trochlear dysplasia (DeJour types B or D). Patients with less than 2-year follow-up were excluded. Radiographic analysis, physical examination, clinical follow-up, patient demographics, and patient-reported outcome measures were obtained for all patients at each visit. Forty patients (44 knees) had complete 2-year or longer follow-up and were included. The majority of patients were female (81.8%) with a mean age of 19.2 years (standard deviation [SD] 6.7; range 13.2-47.0). Follow-up ranged from 2.0 years to 6.8 years (mean 3.6 years, SD 1.35). In total, 45.5% had failed previous surgery for patellar instability. Eight knees developed arthrofibrosis and the overall reoperation rate was 27.3%. No patients had fixation failure and no further surgery was required for instability. The mean preoperative International Knee Documentation Committee score of 50.8 improved to 79.1 (P < .001), and the mean preoperative Kujala score of 56.4 improved to 86.5 (P < .001). Patients reported high satisfaction rates (mean 9.1 of 10). When applicable, 100% of patients returned to work, whereas 84.8% returned to sport. There was no significant radiographic progression of patellofemoral arthritis at a mean of 2.4 years after surgery (SD 1.7). DeJour sulcus-deepening trochleoplasty combined with MPFLR and used with tibial tubercle osteotomy and lateral release is a reliable and effective treatment for recurrent patellar instability due to severe trochlear dysplasia, even in this group with many revisions of previous procedures. IV, case series.

Increased femoral anteversion is associated with inferior clinical outcomes after MPFL reconstruction and combined tibial tubercle osteotomy for the treatment of recurrent patellar instability.

This study aimed at investigating the influence of an increased femoral anteversion angle on clinical outcomes after medial patellofemoral ligament reconstruction and combined tibial tubercle osteotomy for the treatment of recurrent patellar instability. It was hypothesized that an increased femoral anteversion is associated with inferior clinical outcomes. From 2014 to 2016, a total of 144 consecutive patients with recurrent patellar instability were treated with medial patellofemoral ligament reconstruction and combined tibial tubercle osteotomy. The femoral anteversion angle was measured using three-dimensional computed tomography scans. Patients were allocated into group A (femoral anteversion < 20°), group B (femoral anteversion 20°-30°) and group C (femoral anteversion > 30°) based on the value of the femoral anteversion angle. Routine radiography and CT examinations were performed to evaluate the patellar height, trochlear dysplasia, genu valgum, and tibial tuberosity-trochlear groove (TT-TG) distance. The patellar lateral shift distance assessed with stress radiography was used pre- and postoperatively to quantify medial patellofemoral ligament residual laxity under anaesthesia. Patient-reported outcomes (Kujala, IKDC, and Lysholm scores) and patellar maltracking ("J-sign") were evaluated pre- and postoperatively. Finally, subgroup analysis was performed to investigate the influence of an increased femoral anteversion angle on the clinical and radiological outcomes. A total of 66 patients (70 knees) were included with a median follow-up time of 28months (range 24-32). After a minimum of 2years of follow-up, all patient-reported outcomes (Kujala, Lysholm, and IKDC scores) improved significantly, and subgroup analysis showed that group C had significantly lower Kujala scores (75 ± 8 vs. 84 ± 8, P13 = 0.003; 75 ± 8 vs. 82 ± 8, P23 = 0.030), Lysholm scores (81 ± 9 vs. 87 ± 7, P13 = 0.021) and IKDC scores (78 ± 6 vs. 85 ± 7, P13 = 0.001; 78 ± 6 vs. 84 ± 6, P23 = 0.005) than group A and group B. Twelve patients had a postoperative residual J-sign (17.1%), and significant differences were found between group C and group A regarding the rate of residual J-sign (32.1% vs. 4.8%, P13 = 0.003). Postoperatively, group C had a greater patellar lateral shift distance than group A (10 ± 4 vs. 6 ± 4mm, P13 = 0.006) and group B (10 ± 4 vs. 6 ± 3mm, P23 = 0.008). Additionally, patients with a residual J-sign demonstrated greater medial patellofemoral ligament laxity than patients without a residual J-sign (12 ± 4 vs. 9 ± 3mm, P = 0.009). Patients with an increased femoral anteversion angle (> 30°) had inferior postoperative clinical outcomes, including greater patellar laxity, a higher rate of residual J-sign and lower patient-reported outcomes after medial patellofemoral ligament reconstruction and combined tibial tubercle osteotomy for the treatment of recurrent patellar instability. III, retrospective cohort study.

Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability Regardless of Tibial Tubercle–Trochlear Groove Distance and Patellar Height: Outcomes at 1 and 2 Years

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.

THE EVALUATION OF SUPRATROCHLEAR OSSEOUS MORPHOLOGY: AN EPIDEMIOLOGIC STUDY

Introduction: Patellar instability can impede activities of daily life. The morphology of the femoral trochlea has significant involvement in maintaining patellofemoral joint stability. Trochlear dysplasia, or a shallow trochlear groove, has been implicated as a risk factor for recurrent patellar dislocation. A supratrochlear spur in the setting of existing trochlear dysplasia can generate further patellar instability. Trochleoplasty has been popularized by some surgeons for the treatment of recurrent patellar instability in the setting of significant trochlear dysplasia. Despite recommendation of trochleoplasty in treatment of patellar instability in the setting of trochlear dysplasia, much is unknown about the prevalence of trochlear dysplasia and supratrochlear spurs in the general population. The purpose of this study is to investigate the prevalence of supratrochlear spurs and trochlear dysplasia in the population and investigate the relationship between supratrochlear spurs and dysplastic femoral trochleae. Methods: This study was performed at the Cleveland Museum of Natural History, the Hamann Todd Human Osteological Collection. With over 4,000 complete human skeletons, the Hamann Todd osteological collection at the Cleveland Museum of Natural History is the largest collection of osteological specimens with documented demographic data in the Western Hemisphere. We evaluated femora from over 1,000 individuals aged 16-40 years. Each specimen was evaluated for the presence of trochlear dysplasia and supratrochlear spurs. We excluded skeletally immature specimens as well as specimens with visible signs of osteoarthritis or abnormal, bony deformity. The presence or absence of supratrochlear spurs was documented. Abnormal femoral trochleae were photographed in A/P, axial, and lateral views. The width and length of supratrochlear spurs were measured using digital calipers. Results: Of the 1,148 specimens studied, 135 femora from 93 individuals were found to be dysplastic. Amongst these, 9 femora with trochlear dysplasia had supratrochlear spurs. The average age of individuals with dysplastic trochleae in this study was 32.86. Of the 93 specimens identified, 24 were female (25.8%). Additionally, 52% of individuals with dysplastic trochleae were white while 48% were black. Conclusions: There may be an association of supratrochlear spurs with trochlear dysplasia. Though 25.8% of individuals with dysplastic trochleae were female, it is important to note that the Hamann Todd Collection as a whole is 19% female.

Anteromedial Tibial Tubercle Osteotomy Improves Results of Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability in Patients With Tibial Tuberosity–Trochlear Groove Distance of 17 to 20 mm

To compare the midterm clinical outcomes of anteromedialization tibial tubercle osteotomy combined with medial patellofemoral ligament reconstruction (TTO+MPFLR) with MPFLR alone (MPFLRa) for the treatment of recurrent patellar instability (RPI) in patients with a tibial tuberosity-trochlear groove (TT-TG) of 17 to 20mm. From January 2008 to August 2013, patients with RPI and a TT-TG of 17 to 20mm were divided into 2 groups: TTO+MPFLR or MPFLRa. Subjects were evaluated for J sign classification (1-4+); patellar glide (1-4+); the apprehension test; increased femoral anteversion; the Caton index; trochlear dysplasia; TT-TG; and Kujala, Lysholm, International Knee Documentation Committee (IKDC), and Tegner scores. Kujala improvement was the primary outcome. Forty-two subjects were evaluated, 18 in the TTO+MPFLR group and 24 in the MPFLRa group. Mean follow-up time was 40.86months (range, 24-60months). Demographics between the groups were not different. Preoperatively, there was no statistically significant difference between groups regarding J sign classification; patellar glide; the apprehension test; increased femoral anteversion; the Caton index; trochlear dysplasia; TT-TG; and Kujala, Lysholm, IKDC, and Tegner scores. Postoperative J sign classification mean results comparing TTO+MPFLR and MPFLRa, respectively, were 1 and 1.33 (P= .006). Improvement was significantly higher in the TTO+MPFLR group in all scores except forTegner. Kujala improvement, 30.27 and 23.95, respectively (P= .003), was also clinically significant, favoring TTO+MPFLR. Lysholm improvement was 40.5 and 36.2, respectively (P= .02), and IKDC improvement was 38.59 and 31.6, respectively (P=.002). There were no reported recurrent subluxations or dislocations in either group. TTO+MPFLR resulted in better functional outcome scores and patellar kinematics compared with MPFLRa in the surgical treatment of RPI in patients with a TT-TG distance of 17 to 20mm. Level II, prospective comparative study.

Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability Regardless of the Tibial Tubercle Trochlear Groove Distance: Outcomes at 1 and 2 Years

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.

Complications of Tibial Tubercle Surgery

Objectives:Tibial tubercle osteotomy (TTO) is a common procedure that is frequently used in the treatment of recurrent patellar instability and/or patellar chondrosis. Medialization of the tubercle decreases the lateral quadriceps vector of the patella resulting in load shifting away from the lateral patella. Distalization of the tubercle decreases patella height and allows for earlier containment of the patella in the bony walls of the trochlear groove. Anteriorization has been shown to be an effective treatment to unload the inferior lateral patella when chondrosis of the patella is present in this region. Current estimates of this procedure’s complication rates range from 0% to 11%. The purpose of this study was to review the complication rate following TTO performed within an academic sports medicine practice. The hypothesis was that complication rate for TTO is greater than 10% and that the rate of complications with distalization exceeds that of medialization alone.Methods:All patients between May 2009 and May 2015 who underwent a TTO were retrospectively identified. Those with at least 6 months of follow up or a complication within the first 3 months were included for data analysis. Complications were identified and labeled as either major or minor. Major complications were defined as fracture of the tibia, deep infection requiring surgical debridement, nonunion requiring revision fixation, delayed union requiring bone graft, bone stimulation, or screw exchange, arthrofibrosis requiring manipulation under sedation and/or open lysis of adhesions, loss of fixation of the tubercle fragment, and deep vein thrombosis (DVT) whereas minor complications were defined as removal of symptomatic hardware, superficial wound infection, disturbance of cutaneous sensation, and delay in wound healing not requiring surgery.Results:During the study period, 126 TTO were performed. Representing the study cohort are 111 patients, who have at least 6 months of follow up or a complication within 3 months. The mean follow up was 23 months. There were 62 of 126 (49.2%) TTO performed for patellofemoral instability and 23 of 126 (18.2%) for patellofemoral chondral damage. Thirty-eight osteotomies were performed for both instability and cartilage damage (30.2%). Two osteotomies were performed solely for patella alta and one TTO was performed for unspecified reason (2.4%). Of the complications, 28 came following distalization of the tubercle and 4 of these complications represent subsequent tibia fracture. Overall, the complication rate was 28.7 percent; major (17.1%) and minor (11.6%) complication rates are shown in Table 1. Subgroup analysis shows a complication rate of 54% for tubercles that were distalized versus 46% for medialization alone.Conclusion:The rate of total complication for TTO was 28.7%, this is greater than the estimated rate of complication in the current literature. Further, the rate of complications when the tibial tubercle was distalized was greater than when medialized alone suggesting that special considerations be made with this cohort. This high rate of complication is accompanied by a high rate of arthrofibrosis when compared to current literature suggesting the need for preoperative discussion as well as a detailed plan for postoperative rehabilitation to improve motion in patients and decrease the need for subsequent intervention. This study’s findings may redirect patient and physician discussions regarding risks of tibial tubercle osteotomies.Table 1:Complication Frequency Major Complication 17.1% Fracture of Tibia33%Deep Infection0.0%Loss of Fixation1.7%Nonunion0.6%Delayed Union2.8%DVT1.1%Arthrofibrosis requiring surgery8.3% Concomitant Intraarticular Procedures33.3% Concomitant Extraarticular Procedures66.7% Minor Complication 11.6% Removal of Hardware9.4%Superficial Infection1.7%LosstDecrease of Cutaneous Sensation3.9%Wound Dehiscence0.6%

Tibial Tubercle Osteotomies: a Review of a Treatment for Recurrent Patellar Instability.

The goal of this review is to provide an overview of current surgical treatment options for tibial tubercle osteotomies as a treatment for recurrent patellofemoral instability. As such we sought to provide the reader with the most current answers to why treatment practices have changed and how this has affected the outcome of surgical treatment for patellar instability. As our understanding of patellofemoral biomechanics have grown, appropriate surgical and non-surgical treatment options have followed suit to address these findings. A clear understanding of the pathomechanics causing the patient's patellar instability is germane to choosing the most appropriate surgical intervention to address this instability. Likewise, understanding the goal of the intervention chosen-e.g., unloading, realignment-is paramount. These surgical techniques may be technically challenging and surgical specialists with experience in these techniques are recommended for optimal outcomes.

MPFL Reconstruction Combined with Anteromedialization Tibial Tubercle Osteotomy Versus Isolated MPFL Reconstruction in Patients with Recurrent Patellar Instability: A Quasi-Randomized Controlled Trial

Recurrent patellar instability is frequently associated with patellar maltracking. Distal realignment is usually recommended for patients with TT-TG greater than 20mm. Nevertheless, selected patients with subtle abnormalities, TT-TG distance <20mm, may benefit from the distal realignment improving clinical outcomes when combined to MPFL reconstruction in comparison to MPFL reconstruction alone. Compare the clinical outcomes of the anteromedialization tibial tubercle osteotomy (TTO) combined with medial patellofemoral ligament reconstruction (MPFLR) versus MPFLR alone for the treatment of recurrent patellar instability (RPI) in patients with TT-TG 17 to 20 mm presenting its mid-term outcomes. From January 2008 to August 2013, skeletally mature patients with RPI and TT-TG 17-20mm were quasi-randomized into two groups: TTO combined with MPFLR (TTO+MPFLR) or MPFLR alone (MPFLRa). Quasi-randomization: both interventions were explained to the patients and they chose which one to be submitted. Subjects were evaluated for patellar tracking lateralization, patellar glide, apprehension test, increased femoral anteversion, Caton index, trochlea dysplasia by Dejour classification, TT-TG, Kujala, IKDC, Lysholm and Tegner. Forty-two patients composed the study. TTO+MPFLR group was comprised of 18 patients and MPFLRa group was comprised of 24 patients. Demographics between groups were not significantly different related to age, gender, side, and cartilage lesion. Results are presented comparing TTO+MPFLR and MPFLa, respectively, as follows. Follow-up: 41.33±10.26, 40.5±11.63 months, p=0.81. Patellar tracking lateralization preoperatively: 3.33±0.84, 3.25±0.67, p=0.182. Patellar tracking lateralization postoperatively: 1±0, 1.33±0.48, p=0.006. Patellar glide and apprehension test preoperatively: All patients had a positive apprehension test or a patellar luxation at the patellar glide test rated as grade 4 before surgery. Patellar glide postoperatively: 1.17±0.38, 1.21±0.41, p=0.734. Apprehension test postoperatively: none. Increased femoral anteversion: 6%, 25%, p=0.9. Caton index preoperatively: 1.12±0.14, 1.12±0.11, p=0.97. Caton index postoperatively: 1±0.08, 1.12±0.11 (the same preoperatively), p=0.0012. TTO+MPFLR patients submitted to concurrent tibial tubercle distalization: 44%. Trochlea dysplasia: no significant difference between groups, p=0.67. TT-TG preoperatively: 18.5±1.24, 18.04±1.12, p=0.16. TT-TG postoperatively: 10.55±0.83, 18.04±1.12 (the same preoperatively), p<.001. No significant difference was seen in the preoperatively scores (Kujala, IKDC, Lysholm and Tegner) between the groups. Significant improvements were seen in all scores except Tegner from the preoperative baseline to the latest follow-up for both groups. Also, the improvement from the baseline was statistically significant higher in the TTO+MPFLR group compared with the MPFLRa group in all scores, except for Tegner. Kujala improvement: 30.27±4.94, 23.95±8.37, p=0.003, also clinically significant favoring TTO+MPFLR. IKDC improvement: 38.59±7.26, 31.6±8.67, p=0.002. Lysholm improvement: 40.5±9, 36.2±8.9, p=0.02. Tegner improvement: -0.11±0.47, -0.25±0.53, p=0.5. No major complications were described in both groups. TTO combined with MPFLR was better than MPFLRa in the surgical treatment of RPI patients with TT-TG 17-20mm.