The Effect of Aberrant Rotation on Radiographic Patellar Height Measurement Using Canton-Deschamps Index: A Cadaveric Analysis.

The Caton-Deschamps Index (CDI) is a measurement used to evaluate patella alta based on true lateral radiographs; however, no prior study has investigated how altering the degree of radiograph aberrancy affects CDI measurement. The primary and secondary purpose of this study was to evaluate effects of rotational radiographic changes on patella height measurements and compare these findings to MRI measurements, respectively. Five cadaver knees (n = 5) were utilized in this study. True lateral radiographs were obtained for each specimen by using a fluoroscopic C-arm machine. The C-arm was then altered in two planes (axial and coronal) in both the clockwise and counterclockwise direction and radiographs were taken at 5, 10, and 15 degrees of error from the true lateral position. A CDI measurement of each specimen was performed based on sagittal magnetic resonance imaging (MRI) slices and compared with radiographic CDI measurements. Three orthopedic surgeons measured the CDI for each radiograph and MRI performed. Interrater reliability and changes in CDI were analyzed. Clinically significant difference in CDI was set to 0.1. Mean intraclass correlation coefficient was high (≥0.7) at true lateral and at all varying degrees of error. When performing a pairwise comparison of mean CDI from the true lateral position to increasing degrees of error, statistically significant differences were observed in the axial plane. The largest change in CDI measurements was seen with rotational malposition in the axial plane and counterclockwise direction. No statistically significant differences in mean CDI were observed in the coronal plane. The change in CDI from the true lateral position reached an absolute maximum of at least 0.1 in all four scenarios at each tested degree of error. This study found that aberrant radiographic rotation in the axial plane resulted in a significantly different mean CDI measurement when compared with true lateral radiographs. All degrees of error in both directions and in both planes could have a clinically significant effect on CDI (≥0.1). Our findings confirm the importance of a perfect true lateral radiograph when measuring patella height.

Return to Work Following Isolated Opening Wedge High Tibial Osteotomy.

PURPOSE: Patients with isolated medial compartment osteoarthritis and varus deformity may undergo high tibial osteotomy (HTO) to reduce the contact pressure in the medial compartment. The purpose of this investigation is (1) examine the timeline of return to work (RTW) following HTO and (2) evaluate RTW stratified by occupational intensity. METHODS: Consecutive patients undergoing HTO were reviewed retrospectively at a minimum of 2-years postoperatively. Patients completed a subjective work questionnaire, a visual analogue scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire. RESULTS: Thirty-eight patients were included at an average of 9.0 ± 3.3 years postoperatively. Thirty-seven patients (average age 43.4 ± 7.8 years, 91.9% with a Kellgren-Lawrence grade of III/IV) were employed within 3 years prior to surgery. Eighteen patients (48.6%) underwent subsequent surgery with 14 patients (37.8%) receiving a salvage knee arthroplasty at an average of 6.1 ± 3.5 years following HTO. Thirty-five patients (94.5%) returned to work at an average of 2.9 ± 2.0 months. The rate of RTW for sedentary, light, moderate, and heavy duties were 87.5%, 100%, 100%, and 93.3%, respectively, while the duration until RTW was 1.0 months, 1.1 months, 2.4 months, and 3.3 months, respectively. CONCLUSION: In a young and active population with osteoarthritis or varus deformity, an HTO allows patients to return to work; however, patients with high-intensity occupations may be absent from work longer than those with lesser physically demanding occupations. HTO is not a definitive treatment option as nearly 40% of patients underwent knee arthroplasty by 6.1 years postoperatively. LEVEL OF EVIDENCE: IV, case series.

The quadriceps insertion of the medial patellofemoral complex demonstrates the greatest anisometry through flexion.

PURPOSE: A comprehensive understanding of the biomechanical properties of the medial patellofemoral complex (MPFC) is necessary when performing an MPFC reconstruction. How components of the MPFC change over the course of flexion can influence the surgeon's choice of location for graft fixation along the extensor mechanism. The purpose of this study was to (1) determine native MPFC length changes throughout a 90° arc using an anatomically based attachment and using Schöttle's point, and (2) compare native MPFC length changes with different MPFC attachment sites along the extensor mechanism. METHODS: Eight fresh-frozen (n = 8), cadaveric knees were dissected of all soft tissue structures except the MPFC. The distance between the femoral footprint (identified through anatomical landmarks and Schottle's point) and the MPFC was calculated at four attachment sites along the extensor mechanism [midpoint of the patella [MP], the center of the osseous footprint of the MPFC (FC), the superomedial corner of the patella at the quadriceps insertion (SM), and the proximal extent of the MPFC along the quadriceps tendon (QT)] at 0°, 20°, 40°, 60°, and 90° of flexion. RESULTS: Length changes were investigated between the MPFL femoral attachment site and the radiographic surrogate of the MPFL attachment site, Schottle's Point (SP). Paired t tests at each of the four components showed no differences in length change from 0° to 90° when comparing SP to the anatomic MPFC insertion. MPFL length changes from 0° to 90° were greatest at the QT point (13.9 ± 3.0 mm) and smallest at the MP point (2.7 ± 4.4 mm). The FC and SM points had a length change of 6.6 ± 4.2 and 9.0 ± 3.8, respectively. Finally, when examining how the length of the MPFC components changed through flexion, the greatest differences were seen at QT where all comparisons were significant (p < 0.01) except when comparing 0° vs 20° (n.s.). CONCLUSION: The MPFC demonstrates the most significant length changes between 0° and 20° of flexion, while more isometric behavior was seen during 20°-90°. The attachment points along the extensor mechanism demonstrate different length behaviors, where the more proximal components of the MPFC display greater anisometry through the arc of motion. When performing a proximal MPFC reconstruction, surgeons should expect increased length changes compared to reconstructions utilizing distal attachment sites.

Return to Work Following Arthroscopic Meniscal Allograft Transplantation.

PURPOSE: Evaluate the ability of patients to return to work (RTW) following arthroscopic meniscal allograft transplantation (MAT) for meniscal deficiency. METHODS: Consecutive patients undergoing MAT were retrospectively reviewed at a minimum of 2 years postoperatively. Patients completed a subjective work questionnaire, Visual Analogue Scale for pain, Single Assessment Numerical Evaluation, and satisfaction. RESULTS: Forty-seven patients who were employed within 3 years prior to surgery (average age: 30.2 ± 6.9 years) were contacted at an average of 3.5 ± 0.9 years postoperatively. Forty-six patients (97.8%) returned to work by 2.7 ± 2.6 months postoperatively, and 44 patients (93.6%) returned to the same level of occupational intensity. Patients who held sedentary, light, medium, or high intensity occupations were able to RTW at a rate of 100.0%, 100.0%, 88.9%, and 85.7% (P = 0.4) by 1.1 ± 1.0 months, 2.5 ± 2.5 months, 3.5 ± 3.2 months, and 4.3 ± 2.8 months (P = 0.3) postoperatively. Thirty-eight patients (80.9%) were at least somewhat satisfied, and 43 patients (91.5%) would still have the operation if presented the opportunity. No patient underwent revision MAT or conversion to arthroplasty. CONCLUSION: In patients with painful meniscal deficiency, MAT provides a high rate of RTW (97.8%) by 2.7 ± 2.6 months postoperatively. However, some patients may be unable to return to their previous level of occupational intensity. Although statistically insignificant, patients with higher intensity occupations may have a lower rate and longer duration until RTW than those with less physically demanding occupations. Information regarding RTW is imperative for appropriately managing postoperative expectations.

Topographic Analysis of Lateral Versus Medial Femoral Condyle Donor Sites for Oblong Medial Femoral Condyle Lesions.

PURPOSE: To analyze the topographic matching of oblong osteochondral allografts to treat large oval medial femoral condyle (MFC) lesions using computer simulation models. The secondary objective was to determine whether lateral femoral condyle (LFC) grafts would have a similar surface matching when compared with MFC grafts in this setting. METHODS: Human femoral hemicondyles (10 MFCs, 7 LFCs) underwent 3-dimensional computed tomography. Models were created from computed tomography images and exported into point-cloud models. Donor-recipient matches with large condylar width mismatch were excluded. The remaining specimen were divided into 3 donor-recipient groups with 2 defect sizes (17 × 30 mm and 20 × 30 mm): 20 MFC donor (MFCd)-MFC recipient (MFCr), 27 ipsilateral LFC donor (LFCd)-MFCr, and 26 contralateral LFCd-MFCr. Grafts were optimally virtually aligned with the MFCr defect. Mismatch of the articular cartilage and subchondral bone surfaces between the graft and the defect and articular step-off were calculated. RESULTS: MFCd grafts resulted in articular cartilage surface mismatch and peripheral step of less than 0.5 mm for both defect sizes. The subchondral bone surface mismatch was significantly greater than the articular cartilage surface mismatch (P < .01) in both defect sizes). Conversely, the ipsilateral and contralateral LFCd grafts resulted in significantly greater articular cartilage surface mismatch and step-off for both defect sizes when compared to MFCd grafts (P < .01). CONCLUSIONS: Oblong MFC allografts provide acceptable topographic matching for large oval MFC lesions when condylar width differences are minimized. However, concern exists in using oblong LFC allografts for MFC defects, as this can result in increased peripheral step-off and surface mismatch. CLINICAL RELEVANCE: These data reinforce the ability to use oblong MFC osteochondral allograft for treating oval cartilage lesions of the MFC when condylar width is considered. Although other studies have demonstrated LFCs can be used to treat circular defects on the MFC, this may not be true for oblong grafts.

The Effect of Triangulation Simulator Training on Arthroscopy Skills: A Prospective Randomized Controlled Trial.

PURPOSE: To prospectively evaluate the transferability of skills acquired on a low-cost, at-home, nonanatomic triangulation simulation system to cadaveric models. METHODS: We randomized 28 medical students into either a simulator-training group (n = 14) or group with no training (control, n = 14). All subjects were pretested using a standardized checklist of arthroscopic skills on cadaveric knees and shoulders. Training-group subjects practiced on the triangulation simulator for 90 minutes per week for 4 consecutive weeks. Control subjects received no training. All subjects completed a post-test checklist of arthroscopic skills on cadaveric knees and shoulders, as well as 4 training tasks on the simulator. A blinded orthopaedic surgeon evaluated the arthroscopic videos using the Arthroscopic Surgical Skill Evaluation Tool (ASSET) score. RESULTS: Training-group knee and shoulder ASSET scores increased from 12.2 ± 1.85 to 14.6 ± 2.76 (P = .02) and from 14.6 ± 3.5 to 17.9 ± 4.5 (P = .29), respectively. In the control group, knee and shoulder ASSET scores increased from 14.3 ± 3.12 to 14.25 ± 4.67 (P = .99) and from 14.2 ± 2.7 to 17.07 ± 6.7 (P = .58), respectively. There were no significant differences in the mean post-test ASSET scores between the training group and control group for either knee or shoulder arthroscopy. The post-test ASSET safety subscore during knee arthroscopy was significantly higher in the training group (P = .03). The training group was able to complete significantly more simulator tasks compared with controls (P = .003) at post-testing. A significant positive correlation was found between knee arthroscopy performance and the number of tasks completed during simulation post-testing (P = .043). There was no significant correlation between shoulder arthroscopy performance and simulation performance (P = .532). CONCLUSIONS: Basic triangulation skills may be acquired by training on a low-cost, at-home, nonanatomic triangulation simulation system, although the degree of transferability and universal joint applicability, as well as the existence of an early ceiling effect in skill development, could not be shown. LEVEL OF EVIDENCE: Level II, randomized controlled trial.

Return to Sport and Patient Satisfaction After Meniscal Allograft Transplantation.

PURPOSE: To investigate patient return to sport and satisfaction after meniscal allograft transplantation (MAT). METHODS: Patients undergoing MAT using a bone bridge technique between 2013 and 2015 with minimum 2-year follow-up were retrospectively reviewed. They completed a survey regarding return to sport, satisfaction, and subsequent surgery in addition to patient-reported outcome measures. RESULTS: Of 117 patients, 87 (74.4%) were available at an average follow-up of 3.64 years (range, 2.01-5.13 years). The mean age at the time of surgery was 28.99 ± 8.26 years. Lateral MAT was performed in 44 cases (50.6%); medial MAT, 42 (48.3%); and combined medial and lateral MAT, 1 (1.1%). Concomitant procedures were performed in 72 patients (82.7%) including cartilage restoration (n = 65, 74.7%), realignment (n = 9, 10.3%), and anterior cruciate ligament reconstruction (n = 9, 10.3%). Patients experienced significant improvement in the Lysholm score (P < .001), International Knee Documentation Committee score (P < .001), Knee Injury and Osteoarthritis Outcome Score (KOOS)-Quality of Life (P < .001), KOOS-Activities of Daily Living (ADL) (P < .001), KOOS-Pain (P < .001), KOOS-Sports (P = .001), KOOS-Symptoms (P = .003), Short Form 12 physical score (P < .001), and Veterans Rand-12 physical score (P < .001). Reoperation was performed in 26 patients (29.9%); failure occurred in 12 patients (13.8%; total knee arthroplasty in 1, unicompartmental arthroplasty in 2, and total meniscectomy in 9). Overall, 77.0% of patients were satisfied with their outcome. Prior to MAT, 82 patients (94.3%) participated in sporting activities; 62 patients (75.6%) returned to at least one sport at 12.58 ± 6.20 months postoperatively, with 30 (48.4%) reaching their preoperative level of intensity and 72 (87.8%) discontinuing at least one of their preoperative sports. The most common reasons for sports discontinuation postoperatively were prevention of further damage (73.6%), pain with activity (51.4%), fear of further injury (48.6%), surgeon recommendation (33.3%), and swelling with activity (30.6%). Patients were satisfied with their sports participation at a rate of 62.1%. CONCLUSIONS: In a complex patient population undergoing arthroscopic MAT, 75.6% of patients were able to return to at least one sport at an average of 12.58 ± 6.20 months postoperatively. The level of sport declined, with 93.5% of patients restricting involvement to recreational sports after MAT and 48.4% returning to their preoperative level of activity intensity. In addition, 87.8% of patients reported discontinuing a sport in which they had participated preoperatively. The most common reasons for decreasing level of sport were prevention of further damage, pain or swelling with sports, and fear of further injury. The reoperation rate after MAT was 29.9%. Most patients were satisfied with the outcome of surgery, with 77.0% satisfied in general and 62.1% satisfied with their ability to play sports. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Return to Sport Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation.

BACKGROUND: Young patients with symptomatic chondral defects in the medial compartment with varus malalignment may undergo opening wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) (HTO + OCA). Although patients have demonstrated favorable outcomes after HTO + OCA, limited information is available regarding return to sporting activities after this procedure. PURPOSE: To evaluate (1) the timeline to return to sports (RTS), (2) patient satisfaction, and (3) reasons for discontinuing sporting activity after HTO + OCA, and to identify predictive factors of RTS. STUDY DESIGN: Case series; level of evidence, 4. METHODS: Consecutive patients who underwent HTO + OCA for varus deformity and medial femoral condyle focal chondral defects with a minimum 2-year follow-up were retrospectively reviewed. Patients completed a subjective sports questionnaire, satisfaction questionnaire, visual analog scale for pain, and Single Assessment Numerical Evaluation. RESULTS: Twenty-eight patients with a mean age of 36.97 ± 7.52 years were included at mean follow-up of 6.63 ± 4.06 years. Fourteen patients (50.0%) required reoperation during the follow-up period, with 3 (10.7%) undergoing knee arthroplasty. Twenty-four patients participated in sports within 3 years before surgery, with 19 patients (79.2%) able to return to at least 1 sport at a mean 11.41 ± 6.42 months postoperatively. However, only 41.7% (n = 10) were able to return to their preoperative level. The most common reasons for sports discontinuation (n = 20; 83.3%) were a desire to prevent further damage to the knee (70.0%), persistent pain (55.0%), persistent swelling (30.0%), and fear (25.0%). CONCLUSION: In young, active patients with varus deformity and focal medial femoral condyle chondral defects, HTO + OCA enabled 79.2% of patients to RTS by 11.41 ± 6.42 months postoperatively. However, only 41.7% of patients were able to return to their preinjury level or better. It is imperative that patients be appropriately educated to manage postoperative expectations regarding sports participation after HTO + OCA.

Differential Contributions of the Quadriceps and Patellar Attachments of the Proximal Medial Patellar Restraints to Resisting Lateral Patellar Translation.

PURPOSE: To define the contributions of the of the medial patellofemoral ligament (MPFL) and medial quadriceps tendon femoral ligament (MQTFL) to lateral patellar translation as the knee moves through a 90° arc of motion. METHODS: Six pairs of bilateral cadaveric knee specimens (12 knees) were dissected and potted in perfect lateral position using fluoroscopy. An eye screw was placed in the midpoint on the lateral aspect of the patella. Each knee underwent testing in 4 conditions after sequential sectioning: intact, lateral retinacular release, randomized MQTFL or MPFL sectioning, and complete proximal medial patellar restraint (PMPR) sectioning. With a custom machined jig, all knees were tested at 0, 10, 20, 30, 45, 60, and 90° of flexion on an MTS machine with 20N of lateral patellar force applied and displacement recorded. RESULTS: PMPR extensor mechanism insertion on all specimens was identified 50% on the quadriceps tendon and 50% on the proximal aspect of the medial patella. Isolated MPFL sectioning resulted in significantly increased lateral displacement compared to the lateral release state at all flexion angles tested except 0°. There was significantly increased lateral patellar displacement with complete sectioning compared with isolated proximal sectioning at all degrees of knee flexion except 0°. However, complete sectioning following isolated MPFL sectioning did not demonstrate significance at any angle. CONCLUSIONS: Compared with the MQTFL, the MPFL is primarily responsible for resistance to lateral patellar translation throughout a 0° to 90° arc of motion. The MPFL provides a similar resistance to lateral patellar displacement as the fully intact PMPR; however, the MQTFL may contribute to resistance in full extension. CLINICAL SIGNIFICANCE: Proximal medial patellar restraint reconstruction techniques involving both the patellar and quadriceps insertion have been described; however, the unique contributions of the native anatomy to lateral patellar restraint have not been investigated.

Return to Work Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation.

PURPOSE: To assess the timeline of return to work (RTW) following opening-wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) of the medial femoral condyle. METHODS: Consecutive patients undergoing HTO + OCA due to focal chondral deficiency and varus deformity were retrospectively identified and reviewed at a minimum of 2 years following surgery. Patients completed a subjective work questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire. RESULTS: Twenty-eight patients (average age: 36.0 ± 7.9 years) were included at 6.7 ± 4.1 years postoperatively. Twenty-six patients were employed before surgery and 25 patients (96.2%) returned to work following HTO + OCA. However, only 88.5% of patients were able to return to the same level of occupational intensity by 3.5 ± 2.9 months postoperatively. The rate of RTW to the same occupational intensity for sedentary, light, medium, and heavy intensity occupations was 100%, 100%, 88.9%, and 80% (P = .8), whereas the duration of RTW was 9.0 ± 7.1 months, 1.7 ± 1.4 months, 2.7 ± 0.9 months, and 4.2 ± 1.9 months (P = .006), respectively. Two patients (7.7%) underwent knee replacement by 5.3 ± 3.1 years postoperatively due to progression of osteoarthritis in the medial compartment. CONCLUSIONS: In patients with focal chondral deficiency and varus deformity, HTO + OCA provides a high rate of RTW (96.2%) by 3.5 ± 2.9 months postoperatively. However, patients with greater-intensity occupations may take longer to return to work than those with less physically demanding occupations. LEVEL OF EVIDENCE: IV, Retrospective Case Series.

Return to Sport and Outcomes After Concomitant Lateral Meniscal Allograft Transplant and Distal Femoral Varus Osteotomy.

PURPOSE: To evaluate the time and rate of return to sport (RTS), as well as outcomes, in young and active patients receiving concomitant lateral meniscal allograft transplantation (MAT) and distal femoral varus osteotomy (DFVO) for lateral meniscal deficiency and valgus malalignment. METHODS: This was a retrospective study of consecutive patients who underwent concomitant MAT and DFVO by a single surgeon. The exclusion criteria were any concomitant procedures other than cartilage restoration procedures for focal full-thickness cartilage defects of the lateral femoral condyle and less than 2 years of follow-up. At final follow-up, patients were asked to complete a subjective sports questionnaire, the Marx Activity Rating Scale, a visual analog scale (VAS), the Single Assessment Numeric Evaluation, and a satisfaction questionnaire. Changes in patient-reported outcome measures were assessed using nonparametric statistical testing. RESULTS: A total of 21 patients met the inclusion criteria, of whom 17 were included for analysis at an average follow-up of 7.5 years (range, 2.2-13.3 years). The average age at the time of surgery was 23.3 years (range, 16.9-36.2 years), and 76.5% of patients were female patients. The average VAS score decreased from 5.7 preoperatively to 2.6 postoperatively (P = .02). Of the 15 patients who participated in sports within 3 years prior to their surgical procedure, 14 (82.4%) returned to 1 or more sports at an average of 16.9 months (range, 6-36 months); however, only 46.7% were able to return to their preinjury level of participation or higher. Furthermore, 88.2% of patients reported being satisfied with their sport-related outcomes. Direct rates of sport-specific return were as follows: weightlifting, 100%; skiing, 100%; running, 66.7%; and basketball, 50%. CONCLUSIONS: In our study population, concomitant MAT and DFVO afforded a high rate of RTS at an average of 16.9 months postoperatively, as well as a significant decrease in VAS pain scores. These findings are essential to note when counseling patients receiving these procedures who wish to resume sports and physical activities so that they may expect an extensive recovery process before they can RTS. LEVEL OF EVIDENCE: Level IV, case series.

Return to Sport and Work After High Tibial Osteotomy With Concomitant Medial Meniscal Allograft Transplant.

PURPOSE: (1) To examine the timeline of return to sport (RTS) and return to work (RTW) after high tibial osteotomy (HTO) with concomitant medial meniscal allograft transplant (MAT), (2) to evaluate the degree of function on RTS and RTW, and (3) to identify reasons patients do not return to sport- or work-related activity. METHODS: Patients undergoing HTO plus MAT were reviewed retrospectively at a minimum of 2 years postoperatively. The exclusion criterion was any concomitant procedure except cartilage restoration for focal full-thickness medial femoral condylar defects. Patients completed a subjective sport and work questionnaire, a visual analog scale for pain, the Single Assessment Numeric Evaluation, and a satisfaction questionnaire. RESULTS: Twenty-two patients (aged 35.1 ± 8.1 years) were included at 9.3 ± 3.7 years postoperatively. Sixteen patients participated in sports within 3 years before surgery, and 14 patients (87.5%) returned to sport by 9.7 ± 3.8 months postoperatively. Only 7 patients (43.8%) returned to their preinjury status. Eighteen patients were employed within 3 years before surgery, and all patients returned to work; however, only 16 patients (88.9%) returned at the same occupational intensity by 3.1 ± 2.4 months. The rates of RTW for light-, medium-, and heavy-intensity occupations were 100%, 75.0%, and 85.7%, respectively, whereas the duration of RTW was 2.1 months, 2.3 months, and 4.8 months, respectively. Of the patients, 20 (90.9%) reported at least 1 complaint postoperatively, with 13 patients (59.1%) returning to the operating room for recurrent symptoms, including 1 patient who received a knee replacement at 7.75 years postoperatively. CONCLUSIONS: In patients with medial meniscal deficiency and varus deformity, HTO plus MAT provided high rates of RTS (87.5%) and RTW (100%) by 9.7 months and 3.1 months, respectively. It is imperative that clinicians manage expectations because patients may RTS and RTW after HTO plus MAT; however, return to high-intensity activities or occupations may be unlikely or delayed. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Return to sport following isolated opening wedge high tibial osteotomy.

BACKGROUND: The purposes of the study are as follows: (1) examine the timeline of return to sport (RTS) following isolated high tibial osteotomy (HTO), (2) evaluate the degree of participation and function upon RTS and (3) identify reasons that patients do not return or discontinue participation in sport activity. METHODS: Patients undergoing isolated HTO were reviewed retrospectively at a minimum of two years post-operatively. Patients completed a subjective sports questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire. RESULTS: Thirty-eight patients (70.4%) were included at an average of 9.0 ±â€¯3.3 years. Thirty-four patients (average age 42.7 ±â€¯7.2 years, 90.0% with a Kellgren-Lawrence grade of III/IV) participated in sports within three years prior to surgery. Eighteen patients (52.9%) returned to the operating room by the time of final follow-up, including 13 patients (38.2%) who underwent salvage arthroplasty by 6.1 ±â€¯3.6 years following HTO. Thirty patients (88.2%) returned to ≥1 sport at an average of 7.5 ±â€¯5.0 months; however only 41.2% were able to return to preinjury level of participation. CONCLUSIONS: In patients with medial osteoarthritis and varus deformity, isolated high tibial osteotomy provides a high rate (88.2%) of return to sport by 7.5 months postoperatively, yet only a fraction of patients returned to their preinjury level. HTO is not a definitive treatment option as nearly 40% of patients underwent knee arthroplasty by 6.1 years post-operatively. Patient expectations regarding return to sport can be appropriately managed with adequate preoperative patient education. LEVEL OF EVIDENCE: IV.

Analysis of Defect Size and Ratio to Condylar Size With Respect to Outcomes After Isolated Osteochondral Allograft Transplantation.

BACKGROUND: Osteochondral allograft transplantation (OCA) is a successful knee joint preservation technique; however, the effects of defect size and defect size:condyle ratio (DSCR) are poorly understood. PURPOSE: To quantify clinical outcomes of isolated OCA of the knee based on defect size and DSCR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Data from patients who underwent OCA of the knee without major concomitant procedures by a single surgeon were analyzed at a minimum follow-up of 2 years. Osteochondral defect size was measured intraoperatively, and femoral condyle size was measured with preoperative imaging. Patient-reported outcomes, reoperations, and survival rates were analyzed per defect size and DSCR, comparing males and females and patients <40 and ≥40 years old. RESULTS: Sixty-eight patients were included, of whom 57% were male (mean ± SD: age, 34.5 ± 10.3 years; follow-up, 5.2 ± 2.6 years). Mean osteochondral defect size and DSCR were 3.48 ± 1.72 cm2 and 0.2 ± 0.1, respectively. Defect size was larger among males as compared with females (3.97 ± 1.71 cm2 vs 2.81 ± 1.16 cm2, P = .005), while DSCRs were not significantly different between sexes ( P = .609). The cohort as a whole demonstrated improvements in the following scores: Lysholm, International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, and 12-Item Short Form Health Survey Physical ( P < .05). There were 27 reoperations (39.7%) at a mean of 2.5 ± 1.92 years and 8 failures (11.8%) at a mean of 2.62 ± 1.3 years. Mean DCSR was higher among patients with graft failure (0.26 ± 0.20 vs 0.19 ± 0.07, P = .049). After stratification by age, failures among patients ≥40 years old were associated with a larger defect size (mean 5.37 ± 3.50 cm2 vs 3.22 ± 1.32 cm2, P = .03) and higher DSCR (mean 0.30 ± 0.25 vs 0.19 ± 0.06, P = .05) when compared with nonfailures. Failures among patients <40 years old were not significantly associated with defect size or DSCR ( P > .05) as compared with nonfailures. CONCLUSION: Patients undergoing isolated OCA transplantation demonstrated significant clinical improvements and a graft survival of 88.2% at 5.2 years. Failures overall were associated with a larger DSCR, and failures among patients ≥40 years old with a larger DSCR and larger defect size. Increasing defect size among males was positively correlated with some improved outcomes, although this was not maintained in analysis of the DSCR, suggesting similar prognosis after OCA regardless of sex. CLINICAL RELEVANCE: Failed osteochondral allografts are associated with larger defect sizes and defect:condyle ratios in this study, providing additional information to surgeons for appropriate patient consultation.

Predictive Factors and Duration to Return to Sport After Isolated Meniscectomy.

BACKGROUND: Return to sport (RTS) after meniscectomy is an important metric for young, active patients. However, the impact of the duration from surgery to RTS on clinical outcomes is not fully understood and is not reflected in outcome scores. PURPOSE: To establish when patients RTS after meniscectomy and to determine predictive measures for the ability to return to their preinjury activity. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: All patients undergoing meniscectomy between 2016 and 2017 from a single institution were assessed for inclusion. RTS, type of activity, and level of function upon returning were obtained. The minimal clinically important difference (MCID), substantial clinical benefit, and patient acceptable symptom state (PASS) were calculated for the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) questionnaire using anchor-based and distribution-based approaches. Preoperative knee-specific and generic quality-of-life scores were analyzed to determine their predictive power of RTS. A multivariate logistical analysis was also performed to determine which demographic variables corresponded to RTS. RESULTS: Overall, 94 patients (mean age, 51.0 ± 11.1 years) who underwent meniscectomy participated in sports within 6 months of surgery. Of these patients, 76.6% returned to sport without permanent restrictions at a mean of 8.6 ± 6.9 weeks postoperatively. RTS rates for low-, medium-, and high-intensity activities were 75.0%, 70.0%, and 82.5%, respectively. RTS was associated with achieving the PASS for the KOOS-Physical Function short form (PS), KOOS-Pain, and KOOS-Sports (P = .004, P = .007, and P = .006, respectively) but not for the IKDC questionnaire (P = .3). Achieving the MCID was associated with RTS for the KOOS-Sports, KOOS-Pain, and IKDC questionnaire (P < .001, P = .03, and P = .001, respectively). There was no preoperative or intraoperative variable that was predictive of RTS. Preoperative KOOS-PS scores ≥37.8 (area under the curve = 76.3%) and KOOS-Pain scores ≥51.4 (area under the curve = 72.5%) were predictive of RTS. CONCLUSION: Approximately 77% of patients returned to sport after meniscectomy at a mean of 2 months postoperatively. The level of activity intensity did not significantly alter the rate of RTS. Higher preoperative scores on the KOOS-PS and KOOS-Pain were predictive of RTS. Identifying these factors allows physicians to counsel patients on expected outcomes after meniscectomy.

Factors Associated With Clinically Significant Patient-Reported Outcomes After Primary Arthroscopic Partial Meniscectomy.

PURPOSE: The purpose of this study was to establish minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) after meniscectomy and factors associated with achieving these goals. METHODS: A prospectively maintained institutional registry was retrospectively reviewed for all patients undergoing isolated arthroscopic partial meniscectomy from 2014 through 2017. MCID, SCB, and PASS were calculated for the International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscores by using the anchor-based methodology and nonparametric receiver operating characteristic curves. Subscores included joint replacement (JR), physical function (PF), symptoms (Sx), pain, activities of daily living (ADL), sport, and quality of life (QOL). RESULTS: A total of 269 patients were analyzed in the study, which reported outcomes between 6 and 7 months after surgery. The average age of our population was 48.9 ± 12.4 years. Twenty patients reported no change, 53 reported minimal improvement, and 137 reported substantial change after surgery; whereas 59 patients reported worse outcomes. One hundred seventy-seven patients were satisfied and 92 were not satisfied with the outcome of surgery. Established MCID/SCB/PASS for the IKDC, KOOS JR, KOOS PF, KOOS Sx, KOOS Pain, KOOS ADL, and KOOS QOL were 10.6/25.3/57.9, 10.7/13.2/68.3, -8.2/-11.3/26.2, 8.9/7.1/71.4, 9.7/22.2/76.4, 11.0/16.9/89.0, 12.5/27.5/55.6, and 15.6/34.4/46.9, respectively. Higher preoperative scores were associated with reduced odds of achieving MCID and SCB but greater odds of achieving PASS for nearly all scores (P < .05). Workers' compensation status, degenerative tears, medial-sided tears, and root tears were associated with reduced odds of achieving 2 or more clinically meaningful outcomes in 2 or more scores (P < .05). CONCLUSIONS: Clinically meaningful outcomes were established by patient self-assessment. Variables associated with achieving these outcomes include preoperative score (positively correlated with MCID/SCB, negatively correlated with PASS); workers' compensation; degenerative, medial-sided tears; and root tears (remaining negatively correlated with MCID/SCB/PASS). These variables should be accordingly measured for confounding in future outcome reporting.

Establishing Clinically Significant Outcomes After Meniscal Allograft Transplantation.

BACKGROUND: Traditionally, the primary outcome in meniscal allograft transplantation (MAT) has been long-term survivorship; however, short-term clinically significant outcomes are necessary to fully evaluate patient improvement after surgery. PURPOSE: To (1) establish the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) with respect to patient-reported outcome measures (PROMs) and (2) evaluate preoperative and intraoperative variables correlated with achieving these threshold values. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A prospectively maintained institutional registry was queried for all MATs performed between 1999 and 2017. The following PROM scores were collected: International Knee Documentation Committee (IKDC) score, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS). Patients who completed preoperative and postoperative PROMs within a 1-month window were included to calculate the distribution-based MCID at this interval. An anchor question regarding satisfaction with surgery was asked at the same time point and was employed to determine the PASS using nonparametric receiver operating characteristic curve/area under the curve analysis. Multivariate regression analysis was performed to correlate patient demographics, medical history, and concomitant procedures to propensity in achieving the MCID and PASS. RESULTS: A total of 98 patients who underwent MAT met the inclusion/exclusion criteria, of whom 10 underwent concomitant ligamentous procedures, 65 underwent concomitant cartilage procedures, and 7 underwent concomitant realignment procedures. The mean patient age was 29.4 ± 9.0 years, and the mean body mass index (BMI) was 26.8 ± 5.2 kg/m2. The distribution-based MCID and PASS were determined for the Lysholm score (12.3 and 66.5) and IKDC (9.9 and 36.0) as well as the KOOS Pain (9.9 and N/A ), Symptoms (9.7 and 73.0), Activities of Daily Living (9.5 and N/A), Sport (13.3 and N/A), and Quality of Life (14.6 and 53.0) subscales, respectively. A preoperative Short Form Physical Component Summary (SF PCS) score greater than 32.0 was predictive of postoperative satisfaction. Patients with work-related claims had a reduced likelihood of achieving the MCID for the IKDC and the PASS for the KOOS Symptoms. An increased BMI was also associated with failing to achieve the PASS for the KOOS Quality of Life (QOL). CONCLUSION: This study established the MCID and PASS for the Lysholm score, IKDC, and KOOS in patients undergoing MAT. Workers' compensation and higher BMI were associated with failing to achieve clinically significant values. Lower preoperative Lysholm, IKDC, and KOOS scores were predictive of achieving the MCID, while higher preoperative SF PCS scores were associated with achieving satisfaction after MAT.

Use of Allografts in Orthopaedic Surgery: Safety, Procurement, Storage, and Outcomes.

The use of allografts has become a vital option for orthopaedic surgeons in the treatment of a variety of musculoskeletal lesions, ranging from osteochondral defects in the glenohumeral joint to meniscal deficiency in the young athlete. Nevertheless, barriers to treating a patient with an allograft-based procedure may arise from concerns over disease transmission, the navigation of tissue banks that supply allografts, the process of obtaining insurance approval, or optimal storage methods. This review serves to support orthopaedic surgeons in the incorporation of allografts into their practice by quelling these potential concerns. Fresh osteochondral allografts, fresh-frozen meniscal allografts, soft tissue allografts, and off-the-shelf cartilage products are the focus of this review amid broad overviews of allograft safety and tissue bank practices in the United States.

Survivorship of Patellofemoral Osteochondral Allograft Transplantation.

INTRODUCTION: We performed a survivorship analysis of patients treated with patellofemoral osteochondral allograft transplantation (OCA) using either a shell or plug technique and identified variables associated with graft failure. METHODS: Consecutive patients at two institutions who underwent OCA of the patellofemoral compartment between March 1, 2001 to March 1, 2015, were retrospectively identified at minimum 2 years' follow-up. Demographic information, intraoperative findings, and postoperative data were collected. Patients were divided into two groups on the basis of surgical technique (plug group and shell group). Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on second-look arthroscopy. Logistic regression analysis was performed to identify patient- and surgery-specific variables associated with survivorship. RESULTS: Fifty patients were identified (36 women and 14 men; mean age 37.43 ± 8.87 years). Sixteen patients received plug allografts, whereas 34 received shell allografts. Forty percent of patients underwent a concomitant meniscal, ligamentous, malalignment, or chondral procedure. Five patients in the Plug Group (31.3%) underwent reoperation at a mean 1.37 ± 1.34 years, and 28 patients (82.4%) who received Shell OCA underwent reoperation at a mean 1.94 ± 1.92 years. Two patients in the plug group had graft failure at a mean 9.17 ± 0.93 years, whereas 13 patients in the shell group had graft failure at a mean 3.81 ± 2.78 years. Patients with plug allografts demonstrated 100% and 66% survival at 5 and 9.8 years, respectively. For the shell group, survivorship was 65.8% and 37% at 5 and 10.6 years, respectively. Increasing body mass index was associated with failure for the case series overall (odds ratio 1.33, P = .020). Traumatic cause was found to be protective of failure (odds ratio = 0.02, P = .035). CONCLUSIONS: Plug OCA of the patellofemoral compartment can be an efficacious procedure with quality mid-term outcomes. Shell OCA led to high failure rates at midterm outcomes. Increasing body mass index may predispose patients to failure, whereas traumatic cause of their lesion was associated with improved outcomes. LEVEL OF EVIDENCE: Level IV, Therapeutic case series.

The Biomechanical Effects of Limited Lateral Retinacular and Capsular Release on Lateral Patellar Translation at Various Flexion Angles in Cadaveric Specimens.

PURPOSE: To determine the biomechanical effect of limited lateral retinacular and capsular release on lateral patellar translation as a function of constant force at various knee flexion angles. METHODS: Six pairs of bilateral cadaveric knee specimens (12 knees) were obtained from a tissue bank, dissected, and potted in a perfect lateral position based on fluoroscopy. A direct lateral force was applied to the patella through an eye screw in the midpoint of the lateral patella, and each knee underwent testing in the intact state and after lateral retinacular and capsular release. All knees were tested at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of flexion using a custom-machined jig on a materials testing system with a 20-N lateral force applied to the patella. Patellar displacement was recorded and compared for each specimen. RESULTS: Lateral displacement was significantly greater at all degrees of flexion for the lateral-release specimens than for an intact lateral retinaculum (P < .05). Compared with intact specimens, lateral-release specimens experienced 30% more translation at 0° of flexion and between 6% and 9% more lateral translation at 10° to 90° of flexion. CONCLUSIONS: Lateral retinacular and capsular release results in significantly increased lateral patellar translation at all flexion angles compared with intact specimens. This finding suggests that the lateral retinaculum may function as a significant restraint to lateral translation even with intact medial soft-tissue restraints. CLINICAL RELEVANCE: Arthroscopic and open limited lateral retinacular releases should be performed with extreme caution when treating lateral patellar instability given the lateral retinaculum's apparent role as a secondary restraint.