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Abstract

Background:

Patellofemoral instability most commonly affects young patients and is often associated with concomitant chondral injury, the incidence of which increases with each dislocation event. The impact of these chondral injuries on the function and pain levels of patients who undergo isolated medial patellofemoral ligament (MPFL) reconstruction without bony realignment remains unclear.

Purpose/Hypothesis:

The purpose of this study was to compare patient-reported outcome measures (PROMs) between individuals who underwent isolated MPFL reconstruction with concomitant cartilage restoration versus those patients who did not require a concomitant cartilage procedure at the time of their MPFL reconstruction. It was hypothesized that cartilage injury that required intervention in patients with patellofemoral instability would be associated with worse preoperative PROMs compared with patients without chondral injury and that these differences would be mitigated by concomitant surgical intervention to address chondral damage performed in addition to their MPFL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with recurrent patellar instability were collected in an institutional registry beginning March 2014. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic features. PROMs, episodes of recurrent instability, and return to sport (RTS) data were obtained at baseline and annually. Patients were retrospectively assigned to the cartilage intervention group if they underwent concomitant particulated juvenile cartilage allograft, osteochondral allograft, open reduction internal fixation, microfracture, or removal of loose body. Those without intervention or isolated chondroplasty comprised the comparison group. PROMs were assessed at baseline and at 2 and 5 years after surgical intervention.

Results:

A total of 138 patients underwent MPFL reconstruction without bony correction between March 2014 and December 2019. Two patients were excluded for concomitant anterior cruciate ligament reconstruction. A total of 22 patients underwent concomitant cartilage restoration, whereas 114 patients underwent chondroplasty or no concomitant cartilage intervention. In total, 50 patients were evaluated at ≥5 years, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients were evaluated at ≥2 years, of whom 89 (75%) completed follow-up PROMs. All PROMs improved significantly over time except for the Pediatric Functional Activity Brief Scale (Pedi-FABS) (P = .095). Baseline PROMs were significantly lower for the concomitant cartilage injury group compared with the MPFL-only group for Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale (P = .0075), KOOS Pain Score (PS) (P = .0138), and Kujala score (P = .0481). However, at 2 years after surgery, no statistically significant difference in PROMs was found between the cartilage and no-cartilage intervention groups, a finding that was maintained at 5 years after surgery. Patients in the cartilage intervention group displayed a lower overall RTS than patients in the no-intervention group (64.29% vs 92.41%; P = .0103). The patients who achieved RTS had a shorter time to RTS after cartilage intervention compared with no intervention (7.55 vs 9.46 months; P = .0461).

Conclusion:

The treatment of cartilage lesions in addition to MPFL reconstruction for recurrent patellar instability was associated with similar improvement in PROMs compared with isolated MPFL reconstruction without cartilage intervention at 2 and 5 years after surgery, despite lower preoperative PROMs in the group requiring cartilage intervention. Patients who underwent cartilage intervention had lower overall RTS rates. Future work will seek to confirm the durability of these results with longer term follow-up.

Keywords

patellofemoral instability MPFL reconstruction cartilage restoration patient-reported outcome measures

Lateral patellar dislocations are among the most common acute knee injuries in young, active patients, with an incidence of 5 to 43 events per 100,000 individuals annually.^6,14,23 Risk factors for recurrent patellar instability include younger age at time of first dislocation, trochlear dysplasia, patella alta, and an elevated tibial tubercle–trochlear groove distance.²³ In addition to injury of the medial patellofemoral ligament (MPFL), which is associated with lateral patellar dislocation in >90% of cases,¹³ patellar instability carries a considerable risk of cartilage injury, which is estimated to occur in 71% in acute cases and up to 97% of chronic cases.²¹ Of these chondral injuries associated with the instability event, the most common locations are the medial facet and central dome of the patella, followed by the lateral femoral condyle.^15-17 The degree of chondral injury has been shown to worsen with recurrent dislocations versus an isolated event.⁹

Previous work has found that an isolated reconstruction of the MPFL is successful in treating the majority of patients who have patellofemoral instability regardless of tibial tubercle–trochlear groove distance and patellar height.³ These patients demonstrate high rates of return to sport (RTS) and a 2.4% rate of postoperative instability.³ Less is known regarding the effect of chondral injuries sustained in the setting of patellar instability on long-term patient outcomes, although available evidence suggests that high-grade chondral injuries of the patellofemoral joint may worsen clinical outcomes.⁷ In other knee ligamentous injury settings, such as revision anterior cruciate ligament (ACL) surgery, articular cartilage pathology affecting the patellofemoral joint has been linked to lower patient-reported outcome measures (PROMs) at 6 years after surgery.²⁴ Many treatment options are available for full-thickness cartilage lesions that present in the setting of instability, such as marrow stimulation, osteochondral transfer, and cell-based treatments including autograft and allograft cartilage.^8,12 However, the clinical effect of treating full-thickness patellofemoral cartilage lesions present at the time of MPFL reconstruction (MPFLR) is not well understood. We hypothesized that patients with full-thickness cartilage lesions necessitating intervention at the time of MPFLR would exhibit lower PROMs preoperatively but would experience similar improvement in their functional outcomes after concomitant treatment of chondral injuries compared with patients undergoing isolated MPFLR.

Methods

Patient Identification and Data Collection

Patients with recurrent patellar instability were collected in an institutional registry beginning March 2014. All patients who had experienced ≥2 dislocation events or >3 subluxation events were eligible for inclusion. Exclusion criteria included history of previous patellar stabilization procedure, a chondral defect affecting the inferior or lateral patella that could otherwise be offloaded with a tibial tubercle osteotomy, anterior knee pain constituting >50% of their chief complaint, and a “jumping J” sign. All patients underwent primary, unilateral, isolated MPFLR regardless of their bony anatomic features.

Surgical Interventions

Patients underwent primary isolated MPFLR as previously described.³ Cartilage interventions included ≥1 of the following: particulated juvenile cartilage allograft, osteochondral allograft (OCA), open reduction internal fixation, microfracture, or removal of loose body. Patients were indicated for particulated juvenile cartilage allograft for full-thickness lesions >1 cm with intact subchondral bone, whereas OCA was indicated if the subchondral bone was compromised. Open reduction internal fixation was used when patients had an acute osteochondral fracture that was amenable to bioabsorbable screw fixation. Microfracture was used for small, full-thickness lesions. Loose body removal was indicated for osteochondral fractures with a lesion that was not amenable to fixation, most commonly due to a delay in presentation. Patients who underwent no specific intervention for cartilage or who underwent isolated chondroplasty using an arthroscopic mechanical shaver for non–full thickness defects comprised the comparison group.

Outcomes

At baseline and annually, we obtained data on RTS, episodes of recurrent instability, and PROMs including Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QOL) subscale, KOOS Pain Score (PS), Pediatric Functional Activity Brief Scale (Pedi-FABS), International Knee Documentation Committee (IKDC) score, and Kujala score. Radiographic measurements were obtained at baseline. Cartilage lesion characteristics including location, Outerbridge grade, and lesion size were identified intraoperatively.

Statistics

Continuous variables were analyzed using independent 2-sample t test or nonparametric alternative, as appropriate. Variables were evaluated for skewness using Shapiro-Wilk test and visually assessed using histograms. Categorical variables were compared using chi-square or Fisher exact test, where appropriate. Patient-reported outcomes were compared by chondral pathology at 3 time points: baseline, year 2, and years ≥5. Scores were compared using independent 2-sample t tests or Wilcoxon-Mann-Whitney tests, where appropriate. Degree of change in PROM scores was compared by chondral pathology according to 3 time periods: baseline to 2 years, 2 years to ≥5 years, and baseline to ≥5 years. Degree of change was compared using independent 2-sample t tests or Wilcoxon-Mann-Whitney tests, where appropriate.

Results

A total of 138 patients underwent isolated MPFLR between March 2014 and December 2019. Two patients were excluded for undergoing concomitant ACL reconstruction and meniscal repair, respectively, for a total sample of 136 patients. A total of 22 patients underwent cartilage intervention, and 114 patients comprised the comparison group who underwent no cartilage intervention or minimal cartilage intervention with chondroplasty (Figure 1). The mean patient age was 20.8 years, and 59% were female. We found no significant differences in age, sex, or body mass index between the cartilage intervention and comparison groups (Table 1). One patient who underwent isolated MPFLR experienced recurrent instability and underwent revision MPFLR. Table 2 describes the cartilage characteristics for those who underwent concomitant cartilage restoration alongside MPFLR versus MPFLR alone. A majority of patients in each group had isolated patellar cartilage lesions or both patellar and trochlear lesions (77% and 14% vs 82% and 16%, respectively). In both groups, the majority of patellar lesions were inferomedial and the majority of trochlear lesions were on the lateral surface (38% and 60% vs 73% and 74%, respectively). The mean International Cartilage Regeneration & Joint Preservation Society grade of both the patella and trochlea was higher in the cartilage intervention group (3.53 ± 0.98 and 3 ± 0.71, respectively) than in the group without concomitant cartilage intervention (2.71 ± 0.67 and 2.41 ± 0.49, respectively). Of the 22 patients who underwent cartilage surgery, 7 underwent restoration of their chondral defect with particulated juvenile cartilage allograft, 2 underwent OCA, 4 underwent open reduction internal fixation of an osteochondral fragment, 3 underwent microfracture, and 6 underwent removal of an osteochondral loose body (the group that had isolated removal of loose body had lesions that did not necessitate cartilage restoration because the lesions were on nonweightbearing or minimally weightbearing parts of the joint). Figure 2 demonstrates representative repair of patellar cartilage defects with particulated juvenile cartilage allograft, OCA, and open reduction internal fixation.

Figure 1.

STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) diagram. ACLR, anterior cruciate ligament reconstruction; PROM, patient-reported outcome measure.

Table 1

Patient Demographic Characteristics ^a

Variable	MPFLR + Cartilage Intervention	MPFLR Only	P
Age, y	20.82 ± 5.63	19.86 ± 6.13	.3214
Sex
Female	13 (59.09)	84 (73.68)
Male	9 (40.91)	30 (26.32)	.1995
Body mass index, kg/m²	24.32 ± 4.66	23.37 ± 4.11	.4496
Tibial tubercle–trochlear groove distance, mm	15.23 ± 4.55	15.10 ± 4.93	.9901
Caton-Deschamps Index	1.14 ± 0.16	1.14 ± 0.16	.7475
Tourniquet time, min	61.32 ± 20.18	43.65 ± 9.71	.0002
Recurrent instability	0 (0.00)	6 (5.26)	.589
RTS total	12 (64.29)	74 (93.67)	.0103
RTS at same or higher level	9 (75.00)	63 (85.13)	.4317
RTS at lower level	3 (25.00)	11 (14.86)
Time to RTS, mo	7.55 ± 4.25	9.46 ± 3.60	.0461

Data are expressed as n (%) or mean ± SD. Boldface indicates statistical significance. MPFLR, medial patellofemoral ligament reconstruction; RTS, return to sport.

Table 2

Cartilage Lesion Characteristics ^a

Lesion Characteristic	Intervention	No Intervention
Location	(n = 22)	(n = 114)
Patella	17 (77)	93 (82)
Trochlea	2 (9)	1 (1)
Both	3 (14)	18 (16)
Neither	0 (0)	2 (2)
Location on articular surface
Patella	(n = 20)	(n = 111)
Inferomedial	8 (38)	81 (73)
Central	5 (24)	6 (5)
Medial	4 (19)	21 (19)
Inferior	0 (0)	2 (2)
Unknown	4 (19)	1 (1)
Trochlea	(n = 5)	(n = 19)
Lateral	3 (60)	14 (74)
Medial	1 (20)	0 (0)
Central	1 (20)	1 (5)
Unknown	0 (0)	4 (21)
ICRS grade
Patella	3.53 ± 0.98	2.71 ± 0.67
Trochlea	3 ± 0.71	2.41 ± 0.49

Data are expressed as n (%) or mean ± SD. ICRS, International Cartilage Regeneration & Joint Preservation Society.

Figure 2.

Representative cartilage procedures. A, Particulated juvenille cartilage transplation for patellar chondral lesion; B, open reduction internal fixation (ORIF) of patellar osteochondral fracture; C, osteochondral allograft transplation for patellar osteochondral lesion.

Mean tourniquet time was significantly higher in the intervention group at 61.32 ± 20.18 minutes compared with 43.65 ± 9.71 minutes in the no-intervention group (P = .0002). No patients in the concomitant cartilage intervention group and 6 patients in the isolated MPFL group (5.26%) experienced recurrent instability, although we found no statistically significant difference in the incidence between the 2 groups.

In the RTS analysis, 5 patients were excluded from the concomitant cartilage intervention group and 34 patients were excluded from the isolated MPFL group for either incomplete RTS data or not playing a sport before surgery (Table 3). A significantly lower RTS rate was found in patients who underwent cartilage intervention (64.29% vs 92.41%; P = .0103). Patients in the cartilage group who achieved RTS displayed a shorter time to return of 7.55 ± 4.25 months compared with 9.46 ± 3.60 months for patients who underwent MPFLR without cartilage intervention (P = .0461). All 6 patients who experienced recurrent instability were in the MPFLR-only group, and all 6 had returned to sport before experiencing their recurrent instability event.

Table 3

Return-to-Sport Analysis ^a

	MPFLR + Cartilage Intervention	MPFLR Only
Total included patients	22	114
Removed from RTS analysis	5	34
No RTS data	4	20
No sport played before injury	1	14
Total patients included in RTS analysis	17	80

Data are numbers of patients. MPFLR, medial patellofemoral ligament reconstruction; RTS, return to sport.

Overall, 50 patients had ≥5 years of follow-up, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients had ≥2 years of follow-up, of whom 89 (75%) completed follow-up PROMs. All PROMs improved over time except for Pedi-FABS, which had no significant change (P = .095). Baseline patient-reported outcomes were significantly different between the intervention and no-intervention groups for KOOS QOL, KOOS PS, and Kujala scores (P < .05). The baseline KOOS QOL, KOOS PS, and Kujala scores for the intervention group were 17.08 ± 15.93, 33.24 ± 15.81, and 49.80 ± 20.51, respectively, compared with 32.98 ± 20.53, 42.41 ± 12.58, and 60.05 ± 18.19 for the no-intervention group (Table 4). On average, those who did not receive a concomitant cartilage intervention scored higher on all 3 measures at baseline compared with those who underwent concomitant cartilage intervention. However, at 2- or 5-year time points, we found no statistically significant difference in PROMs between the intervention and no-intervention groups or in the change in outcomes scores between timepoints for the 2 groups (Tables 5 and 6; Figure 3).

Table 4

Chondral Pathology and Baseline Patient-Reported Outcomes ^a

Variable	MPFLR + Cartilage Intervention	MPFLR Only	P
KOOS QOL	17.08 ± 15.93	32.98 ± 20.53	.0073
KOOS PS	33.24 ± 15.81	42.41 ± 12.58	.0138
Pedi-FABS	12.73 ± 8.17	13.72 ± 10.03	.8395
IKDC	42.51 ± 19.48	50.30 ± 17.24	.0712
Kujala	49.80 ± 20.51	60.05 ± 18.19	.0481

Data are expressed as mean ± SD. Boldface indicates statistical significance. IKDC, International Knee Documentation Committee; KOOS, Knee injury and Osteoarthritis Outcome Score; Pedi-FABS, Pediatric Functional Activity Brief Scale; PS, Pain Score; QOL, Quality of Life.

Table 5

Chondral Pathology and Patient-Reported Outcomes at 2 Years ^a

Variable	MPFLR + Cartilage Intervention	MPFLR Only	P
KOOS QOL	84.42 ± 15.12	74.09 ± 22.65	.115
KOOS PS	9.79 ± 7.38	9.49 ± 11.10	.3914
Pedi-FABS	13.20 ± 7.88	14.49 ± 9.76	.7957
IKDC	86.82 ± 7.45	84.08 ± 16.11	.8872
Kujala	93.07 ± 6.24	90.59 ± 12.76	.9446

Data are expressed as mean ± SD. IKDC, International Knee Documentation Committee; KOOS, Knee injury and Osteoarthritis Outcome Score; Pedi-FABS, Pediatric Functional Activity Brief Scale; PS, Pain Score; QOL, Quality of Life.

Table 6

Chondral Pathology and Patient-Reported Outcomes at ≥5 Years ^a

Variable	MPFLR + Cartilage Intervention	MPFLR Only	P
KOOS QOL	83.33 ± 15.14	72.66 ± 23.53	.3801
KOOS PS	8.70 ± 12.71	12.28 ± 13.05	.3862
Pedi-FABS	10.67 ± 4.18	11.68 ± 6.80	.729
IKDC	81.08 ± 15.69	81.66 ± 16.90	.9496
Kujala	90.17 ± 10.40	89.88 ± 13.62	.8729

Figure 3.

Patient-reported outcome measures and change over time (years). Error bars represent the 95% CI. IKDC, International Knee Documentation Committee; KOOS, Knee injury and Osteoarthritis Outcome Score; MPFLR, medial patellofemoral ligament reconstruction; Pedi-FABS, Pediatric Functional Activity Brief Scale; PS, Pain Score; QOL, Quality of Life.

Discussion

This study found that patients with recurrent patellar instability and associated full-thickness chondral injury that warranted surgical intervention had worse PROMs preoperatively compared with patients with recurrent patellar instability without substantial cartilage pathology. However, postoperatively, patients who underwent intervention for their cartilage injury in addition to MPFLR had resolution of this difference, and at 2 and 5 years after surgery their PROMs were similar to those in the MPFLR-alone group. We additionally found that patients undergoing concomitant cartilage intervention displayed a lower overall RTS rate with a shorter mean time to RTS compared with patients undergoing MPFLR alone.

The location of cartilage lesions of the patella is thought to be indicative of the primary pathomechanics of the injury. Medial cartilage lesions are most commonly seen in the setting of instability,⁴ whereas lateral cartilage lesions are more commonly noted in settings of lateral patellar overload.² In this study, patients with full-thickness, lateral facet cartilage lesions were excluded because these patients may benefit from a tibial tubercle osteotomy to offload laterally based lesions.²⁰

Recurrent patellar instability carries a high incidence of concomitant cartilage injury. Salonen et al¹⁹ followed a cohort of 20 patients who sustained first-time lateral patellar dislocations that were managed nonoperatively over an 8-year follow-up period; the investigators found that 70% of patients sustained a patellar chondral injury that was apparent on primary magnetic resonance imaging, whereas 50% (10/20) of patients had grade 3 to 4 changes in the patellofemoral compartment at time of follow-up. Additionally, 50% of patients exhibited some degree of tibiofemoral arthritis at the time of follow-up with the majority of these lesions seen in the lateral compartment of the knee, suggesting that an acute insult to the knee with a single patellar dislocation event may predispose to eventual global joint degeneration in certain cases.¹⁹ Vollnberg et al²¹ cross-sectionally assessed patients with patellar instability who were classified as acute, recurrent, or chronic dislocators and found that these groups had respective rates of patellar cartilage lesions of 71%, 82%, and 97%.

The long-term clinical implications of a cartilage injury sustained acutely after patellofemoral dislocation remain unclear. Gonzalez at al⁷ found that patients with grade III or IV defects of the patellofemoral joint at the time of isolated MPFLR demonstrated poorer KOOS knee-related quality of life scores than patients without high-grade chondral injuries at a mean of 4.8 years after surgery.

The data regarding treatment of cartilage lesions present in the setting of patellofemoral instability have likewise been mixed. Holliday et al¹⁰ reviewed a cohort of 231 patients who underwent isolated MPFLR for patellofemoral instability and did not find any correlation of preoperative cartilage lesion presence, size, or grade with postoperative Banff Patella Instability Instrument 2.0 (BPII 2.0) scores preoperatively or at 12- or ≥24-month follow-up. In contrast, in a case series of 44 patients, of whom 4 patients had substantial cartilage injury at the time of surgery, Christiansen et al¹ found that patients with grade III or IV patellofemoral chondral injuries at the time of MPFLR had persistent chronic knee pain. In our study, using 5 different PROMs, we observed lower KOOS QOL, KOOS PS, and Kujala scores preoperatively in the cartilage intervention group and no difference in Pedi-FABS and IDKC scores between groups. After cartilage intervention, no differences in PROMs between groups were found at 2 years postoperatively.

The RTS rate has previously been found to be 88% to 90% after isolated MPFLR.³ In contrast, cartilage restoration surgery was shown to have a mean RTS of 76% in a meta-analysis of 2549 patients conducted by Krych et al.¹¹ A lower RTS rate was associated with cartilage surgery in the current study, in which we found a 64% RTS rate in the cartilage intervention group versus 92% in the MPFLR-alone group. Interestingly, we found a shorter time to RTS of 7.55 months in the cartilage intervention group compared with 9.46 months in the MPFLR-alone group. Furthermore, we found no difference between groups in RTS when considering level of sport.

The effect of focal cartilage lesions on patient outcomes was previously studied in the setting of ACL reconstruction. In a study using the Norwegian and Swedish National Knee Ligament Registry, 8476 patients who underwent isolated ACL reconstruction were assessed for the effect of full-thickness cartilage lesions present at the time of injury on outcomes at 2 years after surgery.¹⁸ The investigators found that patients with full-thickness cartilage lesions reported worse outcomes on all of the KOOS subscales compared with patients without cartilage injuries.¹⁸ A systematic review of 27 studies investigating the relationship between cartilage injuries and outcomes after ACL reconstruction likewise found that overall, cartilage injuries were correlated with poorer outcomes after ACL reconstruction, including lower RTS rates.⁵ It is well established that both ACL injury and MPFL injury carry the risk of long-term degeneration of the knee^19,22; however, further studies are needed to better understand the implications of concomitant full-thickness cartilage injuries in the setting of MPFL injury.

There are certain limitations to this study. The procedures performed for cartilage injury were heterogeneous and were based upon the individual nature of each patient's pathology. Importantly, however, the group of patients who underwent cartilage surgery exhibited significantly worse PROMs than the MPFLR-only intervention group preoperatively. A comparison group was not available of patients with full-thickness chondral lesions who did not undergo any cartilage intervention. Small sample sizes restricted our ability to conduct more in-depth subanalyses of outcomes. Strengths of this study include its prospectively collected data in an institutional registry that included multiple assessment measures of both objective and subjective outcomes as well as >5 years of follow-up for patients undergoing a cartilage intervention in the setting of primary MPFLR.

Conclusion

In this cohort of patients undergoing MPFLR for recurrent patellar instability, patients with a concomitant full-thickness cartilage injury necessitating surgical intervention demonstrated lower PROMs preoperatively compared with patients without full-thickness cartilage injuries. We found that despite a lower RTS rate among patients with full-thickness cartilage lesions, PROMs normalized between groups by 2 years after surgery and remained stable at >5 years after surgery. We conclude that addressing concomitant cartilage injuries at the time of MPFLR can allow for optimal outcomes to be obtained that are equivalent to those of patients who did not require concomitant cartilage procedures at the time of their patellar stabilization. Future work will seek to confirm the durability of these results with longer-term follow-up.

Footnotes

Final revision submitted April 21, 2025; accepted June 4, 2025.

One or more of the authors has declared the following potential conflict of interest or source of funding: With grant support provided to his institution, J.T.N. was supported in part by funds from the Clinical Translational Science Center, National Center for Advancing Translational Sciences (NCATS) (grant No. UL1-RR024996). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding source, NCATS, based in Rockville, Maryland. B.E.S.S. is a consultant for Arthrex and has received research support from ConMed. Her husband is a consultant for and receives IP royalties from Arthrex. E.R.D. is a consultant for ConMed. Her husband is a consultant for Metronic. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Ethical approval for this study was obtained from the Hospital for Special Surgery (IRB #2014-123).

ORCID iDs

Michael R. Davies

William A. Marmor

Natalie K. Pahapill

Audrey C. Wimberly

Joseph T. Nguyen

Beth E. Shubin Stein

Elizabeth R. Dennis

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Effect of Cartilage Injuries on Medial Patellofemoral Ligament Reconstruction Outcomes at Midterm Follow-up

Abstract

Background:

Purpose/Hypothesis:

Study Design:

Methods:

Results:

Conclusion:

Keywords

Methods

Patient Identification and Data Collection

Surgical Interventions

Outcomes

Statistics

Results

Discussion

Conclusion

Footnotes

ORCID iDs

References