Accuracy and Reliability of Software Navigation for Acetabular Component Placement in THA: An In Vitro Validation Study.

Background and Objectives: Intraoperative fluoroscopy can be used to increase the accuracy of the acetabular component positioning during total hip arthroplasty. However, given the three-dimensional nature of cup positioning, it can be difficult to accurately assess inclination and anteversion angles based on two-dimensional imaging. The purpose of this study is to validate a novel method for calculating the 3D orientation of the acetabular cup from 2D fluoroscopic imaging. Materials and Methods: An acetabular cup was implanted into a radio-opaque pelvis model in nine positions sequentially, and the inclination and anteversion angles were collected in each position using two methods: (1) a coordinate measurement machine (CMM) was used to establish a digitalized anatomical coordinate frame based on pelvic landmarks of the cadaveric specimen, and the 3D position of the cup was then expressed with respect to the anatomical planes; (2) AP radiographic images were collected, and a mathematical formula was utilized to calculate the 3D inclination and anteversion based on the 2D images. The results of each method were compared, and interrater and intrarater reliably of the 2D method were calculated. Results: Interrater reliability was excellent, with an interclass correlation coefficient (ICC) of 0.988 (95% CI 0.975-0.994) for anteversion and 0.997 (95% CI 0.991-0.999) for inclination, as was intrarater reliability, with an ICC of 0.995 (95% CI 0.985-0.998) for anteversion and 0.998 (95% CI 0.994-0.999) for inclination. Intermethod accuracy was excellent with an ICC of 0.986 (95% CI: 0.972-0.993) for anteversion and 0.993 (95% CI: 0.989-0.995) for inclination. The Bland-Altman limit of agreement, which represents the error between the 2D and 3D methods, was found to range between 2 to 5 degrees. Conclusions: This data validates the proposed methodology to calculate 3D anteversion and inclination angles based on 2D fluoroscopic images to within five degrees. This method can be utilized to improve acetabular component placing intraoperatively and to check component placement postoperatively.

Influence of Medial Meniscus Bucket-Handle Repair in Setting of Anterior Cruciate Ligament Reconstruction on Tibiofemoral Contact Mechanics: A Biomechanical Study.

PURPOSE: To compare the impact of an inside-out repair versus meniscectomy of a medial meniscus bucket-handle tear in restoring native contact areas and pressures across the tibial plateaus in the setting of an anterior cruciate ligament (ACL) reconstruction (ACLR). METHODS: Ten fresh-frozen cadaveric knees were tested in 6 knee conditions (1: intact; 2: ACL torn and bucket-handle tear of medial meniscus, flipped; 3: bucket-handle tear of medial meniscus, reduced; 4: bucket-handle tear of medial meniscus, repaired via inside-out vertical mattress suture technique; 5: ACLR with bone patella tendon bone autograft and bucket-handle repair; 6: ACLR and medial meniscus bucket-handle tear debridement) at 4 flexion angles (0°, 30°, 45°, and 60°), under a 1,000-N axial load. Contact area and pressure were measured with Tekscan sensors. RESULTS: ACLR with a concurrent medial meniscectomy for a medial meniscus bucket-handle tear resulted in significantly decreased contact area (P < .05) and increased mean and peak pressure in both the medial and lateral compartments across all tested flexion angles (P < .05). The ACLR with medial meniscectomy state also demonstrated significantly lower contact area than the bucket-handle repair state between 30° and 60° of flexion (all P < .05). CONCLUSIONS: Resection of a bucket-handle medial meniscus tear concurrent with an ACLR resulted in significant increases in mean and peak contact pressures in not only the medial but also the lateral compartment. Preservation of the medial meniscus in the face of a bucket-handle tear is essential to more closely restore native tibiofemoral biomechanics. CLINICAL RELEVANCE: The increased mean and peak tibiofemoral contact pressure seen with excision of a bucket-handle medial meniscus tear would over time result in increased cartilaginous degradation and resultant osteoarthritis. Decreasing both of these factors through concomitant ACLR and inside-out bucket-handle meniscal repairs should improve patient outcomes by restoring knee biomechanics and kinematics closer to that of the native state.

Rehabilitation and return to activity criteria after operative management of chronic exertional compartment syndrome of the leg: a systematic review.

OBJECTIVES: Endurance athletes with chronic exertional compartment syndrome (CECS) frequently require fasciotomy to return to activity, but there are no existing comprehensive evidence-based rehabilitation guidelines. We aimed to summarize rehabilitation protocols and return to activity criteria after CECS surgery. METHODS: Through a systematic literature review, we identified 27 articles that explicitly defined physician-imposed restrictions or guidelines for patients to resume athletic activities following CECS surgery. RESULTS: Common rehabilitation parameters included running restrictions (51.9%), postoperative leg compression (48.1%), immediate postoperative ambulation (44.4%), and early range of motion exercises (37.0%). Most studies (70.4%) reported return to activity timelines, but few (11.1%) utilized subjective criteria for guiding return to activity. No studies utilized objective functional criteria. CONCLUSIONS: Rehabilitation and return to activity guidelines after CECS surgery remain poorly defined, and further investigation is needed to develop such guidelines that will enable endurance athletes to safely return to activities and minimize recurrence.

Return to Sport After Fasciotomy for Chronic Exertional Compartment Syndrome of the Forearm: A Systematic Review.

BACKGROUND: Forearm chronic exertional compartment syndrome (CECS) can represent considerable functional impairment in certain active populations, particularly motorcycle racers. Patients with forearm CECS frequently require fasciotomy to relieve symptoms and return to sport (RTS). PURPOSE: To evaluate the rate at which athletes RTS after fasciotomy for forearm CECS and to compare RTS outcomes between fasciotomy techniques. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review of the PubMed, Scopus, and Cochrane databases was performed from database inception to December 2022 to identify all published reports of forearm CECS managed with fasciotomy. Included studies were analyzed for demographic information, surgical approaches, rehabilitation parameters, RTS rates, time from surgery at which athletes resumed sport, complications, and recurrence. RESULTS: A total of 38 studies (15 level 4 case series, 23 case reports) accounting for 500 patients (831 forearms) who underwent open fasciotomy (112 patients), minimally invasive fasciotomy (166 patients), and endoscopically assisted fasciotomy (222 patients) satisfied inclusion criteria. Most patients (88.0%) were motorcycle racers. The overall RTS rate at any level (RTS-A) was 94.2% (97.3%, 92.2%, and 98.5% for the open fasciotomy, minimally invasive fasciotomy, and endoscopically assisted fasciotomy groups, respectively; P = .010), and the overall RTS at preinjury level or higher was 86.8% (95.9%, 85.6%, and 95.2% for the open fasciotomy, minimally invasive fasciotomy, and endoscopically assisted fasciotomy groups, respectively; P = .132). There was a significant difference in RTS-A between the minimally invasive fasciotomy and endoscopically assisted fasciotomy groups (P = .004). The overall RTS time was 5.1 ± 2.3 weeks, patient satisfaction was 85.1%, and the recurrence rate was 2.4%, and there were no significant differences between fasciotomy approach groups (P = .456, P = .886, and P = .487, respectively). CONCLUSION: Patients who underwent fasciotomy for forearm CECS had high rates of RTS, quick RTS time, high levels of satisfaction, and low rates of recurrence. Outcomes were largely similar between the 3 fasciotomy approaches.

Considerations for revision anterior cruciate ligament reconstruction: A review of the current literature.

Background: Failure rates among primary Anterior cruciate ligament reconstruction range from 3.2 to 11.1 %. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement. Methods: The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes, and return to sport (RTS) for patients who undergo revision ACLR. Results: In revision ACLR patients, those receiving autografts are 2.78 times less likely to experience a re-rupture compared to patients who receive allografts. Additionally, individuals with properly positioned tunnels and removable implants are considered strong candidates for one-stage revision procedures. Conversely, cases involving primary tunnel widening of approximately 15 mm are typically indicative of two-stage revision ACLR. These findings underscore the importance of graft selection and surgical approach in optimizing outcomes for patients undergoing revision ACLR. Conclusion: Given the high rates of revision surgery in young, active patients who return to pivoting sports, the literature recommends strong consideration of a combined ACLR + anterolateral ligament (ALL) or lateral extra-articular tenodesis (LET) procedure in this population. Unrecognized posterolateral corner (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Consider revision ACLR with combined slope-reducing tibial osteotomy in cases of posterior tibial slope greater than 12°.

Evaluation of Failed ACL Reconstruction: An Updated Review.

Failure rates among primary Anterior Cruciate Ligament Reconstruction (ACLR) range from 3.2% to 11.1%. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement. The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes and return to sport (RTS) for patients who undergo revision ACLR. There is a convincingly higher re-tear and revision rate in patients who undergo ACLR with allograft than autograft, especially amongst the young, athletic population. Unrecognized Posterior Cruciate Ligament (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Given the high rates of revision surgery in young active patients who return to pivoting sports, the authors recommend strong consideration of a combined ACLR + Anterolateral Ligament (ALL) or Lateral extra-articular tenodesis (LET) procedure in this population. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Careful consideration of patient-specific factors such as age and activity level may influence the success of ACL reconstruction. Additional technical considerations including graft choice and fixation method, tunnel position, evaluation of concomitant posterolateral corner and high-grade pivot shift injuries, and the role of excessive posterior tibial slope may play a significant role in preventing failure.

Tibial Tubercle Trochlear Groove Distance Does Not Correlate With Patellar Tendon Length in Patients Who Underwent Anterior Cruciate Ligament Reconstruction.

Purpose: To examine the relationship between tibial tubercle-trochlear groove (TT-TG) distance and patellar tendon length. Methods: All healthy athletes who underwent anterior cruciate ligament reconstruction who had a magnetic resonance imaging (MRI) study of the knee on file between July 2018 and June 2019 at a single institution were retrospectively reviewed. Exclusion criteria included patients without an MRI study of the knee on file or with an MRI of insufficient quality precluding reliable calculation of TT-TG and patellar tendon length. MRIs were reviewed to calculate TT-TG, patellar tendon length, and Caton-Deschamps Index (CDI). Patient charts were reviewed to obtain anthropometric characteristics including sex, concomitant injuries, and previous knee procedures as well as age at time of MRI. Spearman correlations were used to assess the relationship between TT-TG, patellar tendon length, and CDI, with regression analysis performed to assess for relationships between TT-TG, patellar tendon length, and patient-specific factors. Results: Overall, 235 patients (99 female [42.1%], 136 male [57.9%]; mean age: 30.0 years [23.0; 40.0]) were included. Inter-rater reliability between the 2 reviewers was 0.888 for TT-TG, 0.804 for patellar tendon length, and 0.748 for CDI, indicating strong agreement. The correlation between TT-TG and patellar tendon length was 0.021, indicating no true relationship. The correlation between TT-TG and CDI was -0.048 and that of patellar tendon length and CDI was 0.411, indicating a weak positive relationship. Regression analysis found that male sex is strongly correlated with a longer patellar tendon length (odds ratio 2.65, 95% confidence interval 1.33-3.97, P < .001). Conclusions: In this study, no correlation was found between TT-TG and patellar tendon length or CDI. Male sex was correlated with a longer patellar length. Level of Evidence: Level III.

Patients' under 25 subjective readiness to return to sport after ACL reconstruction with bone-patellar-bone grafts: Autograft vs. allograft.

Purpose: To assess the difference in perceived readiness to return to sport (RTS) within the first year postoperative period between individuals undergoing anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BTB) autografts or allografts. Methods: This was a prospective cohort study of patients undergoing primary ACL reconstruction done either with BTB autograft or allograft from 2010 to 2018. Skeletally mature patients aged 14 to 25 were eligible for inclusion. Patients completed the Marx Activity Rating Scale (MARS) questionnaire postoperatively evaluating perceived ability to perform various activities to compare subjective ability to RTS. Those patients who were outside outlined cohort age, failed to complete a single post-operative survey, underwent revision procedures, or underwent simultaneous or staged additional ligament surgery were excluded. Results: Fifty-nine patients (20.1 ± 3.19 years, 57.6 % Male) were included in the study. Sixteen patients underwent ACL reconstruction with allograft (19.8 ± 3.43 years) while 43 patients received autograft (20.2 ± 3.13). At 3 months autograft recipients reported higher perceived ability to cut (P = .003). At 6-months, allograft recipients reported higher perceived ability to run (P = .033), cut (P = .048), and decelerate (P = .008) as well as a higher overall perceived ability to RTS (P = .032). At all other times, there was no significant difference between cohorts' subjective readiness to perform activities. Conclusion: The results of this study indicate that at times within the first year of recovery following ACL reconstruction, patients who receive allografts and autografts may have significantly different perceived ability to perform activities or RTS. However, while present at various times throughout the first year of recovery, any difference in perceived ability to perform activities or in overall RTS is no longer present at 12 months. Level of evidence: Level II, Prospective cohort study.

Return to play after UCL injury in gymnasts.

BACKGROUND: Injuries to the ulnar collateral ligament (UCL) are commonly reported in traditional overhead sports. Conversely, there is a lack of evidence outlining management and return to play (RTP) outcomes for gymnasts. This study aimed to evaluate RTP and patient reported outcomes (PROs) in gymnasts after operative and non-operative treatment of UCL injuries. METHODS: Gymnasts who presented with UCL injury and underwent operative and non-operative treatment were evaluated. Patient reported outcomes were collected via telephone: Conway-Jobe Scale, Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC) Score, Mayo Elbow Performance (MEP) Score, and quick DASH (qDASH) and Timmerman-Andrews (TA) Elbow Score. RESULTS: Nine patients met inclusion criteria and were available for follow-up. Five were initially treated operatively and four were initially treated non-operatively. The operative group initially consisted of three ulnar collateral ligament reconstructions (UCLR) and two UCL repairs with internal bracing. One patient crossed over to the operative group after failing non-operative treatment and underwent UCLR four months post injury. Overall, 66.7% and 100% of operatively and non-operatively treated gymnasts were able to return to play, respectively. At final follow-up, the operative groups' mean KJOC, MEP, TA, and qDASH scores were: 68.4 ± 7.7, 97.5 ± 2.7, 90.8 ± 10.7, and 1.9 ± 3.0, respectively. For the non-operative group, the mean scores were 67.4 ± 9.0, 71.7 ± 5.8, 71.7 ± 14.4, and 11.4 ± 9.9, respectively. Treatment satisfaction for the operative group was 81.7 ± 27.5 compared to 80.6 ± 34.5 in the non-operative group. Odds ratios indicated no differences between groups. CONCLUSION: Both operative and non-operative interventions for UCL injuries in gymnasts can provide favorable outcomes with respect to return to play and subjective patient-reported outcomes. Further research is warranted to determine optimal treatment, especially regarding indications for operative vs. nonoperative treatment, of UCL injury based on injury severity and location in gymnasts. LEVEL OF EVIDENCE: Case series; Level III Evidence.

Analysis of Patients Who Undergo Index Arthroscopy With Biopsy but Not Implantation for Staged Chondrocyte Cell Transplantation.

Background: Autologous chondrocyte implantation (ACI) and matrix-induced autologous chondrocyte implantation (MACI) are 2-stage procedures requiring an index full-thickness cartilage biopsy. Only a portion of patients ultimately undergo second-stage ACI/MACI. Purpose: To identify patients with articular cartilage defects who underwent arthroscopic debridement with biopsy for ACI/MACI and compare those who did with those who did not proceed with implantation within 2 years after biopsy. Additionally, the authors sought to identify why patients did not proceed with implantation. Study Design: Case-control study; Level of evidence, 3. Methods: Patients who underwent arthroscopy and autologous chondrocyte biopsy from January 1, 2015, to December 31, 2019, and who had minimum 2-year follow-up data were grouped into those who proceeded with second-stage ACI/MACI (implant group; n = 97) and those who did not (biopsy group; n = 63). Demographic factors, cartilage defect characteristics, and preoperative International Knee Documentation Committee (IKDC) scores were analyzed. Patients in both groups were evaluated postoperatively using the IKDC, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) for pain, and patients who did not undergo implantation were asked for their reasoning. Results: Body mass index (BMI) (P < .001) and Outerbridge grades at index arthroscopy (P = .047) were significantly higher for the implant group than the biopsy group. Both groups had significantly improved IKDC scores from their initial presentation to final follow-up (implant group: 46.4 ± 16.2 preoperative vs 69.6 ± 20.6 postoperative [P < .001]; biopsy group: 47.2 ± 15.9 preoperative vs 70.7 ± 19.1 postoperative [P < .001]); however, the level of improvement did not differ significantly between groups. Postoperative WOMAC, SANE, and VAS pain scores were also similar between groups. In the biopsy group, 23 patients (37%) cited symptom resolution or activity level improvement after initial arthroscopy as the reason for not proceeding with implantation. Conclusion: Patients who proceeded to the second stage of chondrocyte implantation via either ACI or MACI had higher-grade articular defects and higher BMI compared with those who underwent biopsy with concomitant debridement chondroplasty alone. Postoperative outcomes were similar between the groups.

Surgical management of acute, high-grade acromioclavicular joint separations: a systematic review.

Background: While a number of treatment options exist for repair of acute, high-grade acromioclavicular joint (ACJ) separation, none have emerged as the standard of care. The purpose of this study was to systematically review the literature on surgical treatment of acute, high-grade (Rockwood grades III-V) ACJ separations in order to compare outcomes between direct fixation and tendon graft ligament reconstruction. Methods: A systematic review of the literature evaluating outcomes for acute ACJ separation treatment with direct fixation or free biologic tendon graft reconstruction was performed. The following databases were examined: the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (1980-2021), and Embase (1980-2021). Studies were included if they reported a mean time to surgery as <6 weeks, contained >10 patients with a minimum 1-year follow-up, and reported clinical or radiographic outcomes. Results: A total of 52 studies met the inclusion criteria. Seven studies reported outcomes following tendon graft ligament reconstruction (n = 128 patients). There were multiple methods of direct fixation. Thirty-three studies utilized suture button constructs (n = 1138), 16 studies used hook plates (n = 567), 2 studies used coracoclavicular screws (n = 94), 2 studies used suture fixation (n = 93), 2 studies used suture anchor (n = 55), 2 studies used suture cerclage fixation (n = 87), 1 used single multistrand titanium cable (n = 24), and 1 used K wire (n = 11). The mean follow-up Constant scores ranged from 77.5 to 97.1 in the fixation group compared to 90.3-96.6 in the tendon graft group. The mean visual analog scale scores ranged from 0 to 4.5 in the fixation group and 0.1-1 in the tendon graft group. Net CC distance ranged from 17.5 to 3.6 mm in the fixation group and 7.4-4 mm in the tendon graft group. The revision rates ranged from 0.0% to 18.18% in the direct fixation group and 5.88%-17% in the tendon graft group. Conclusion: Direct fixation and tendon graft reconstruction for management of acute, high-grade ACJ separations have similar patient subjective and radiographic outcomes, as well as complication and revision rates at a minimum 1-year follow-up.

Adolescent Quadriceps Tendon Rupture, an Early Complication After ACL Reconstruction: A Case Report.

CASE: A healthy adolescent male patient initially presented with complete rupture of the anterior cruciate ligament (ACL) after a plant-twist injury during a high school football game. Four weeks after ACL reconstruction with autograft bone-patella tendon-bone, the patient slipped and fell, sustaining hyperflexion of the knee, resulting in rupture of the ipsilateral quadriceps tendon. CONCLUSION: Although this rare complication has previously been reported in the adult population, to the best of our knowledge, this is the first known report of an adolescent patient sustaining a quadriceps tendon rupture after ACL reconstruction.

Clinical and Patient-Reported Outcomes for Acute Acromioclavicular Joint Fixation are Similar With or Without Allograft Augmentation.

Purpose: To compare functional outcomes, complications, and revision rates between allograft reconstruction and graftless fixation techniques for the treatment of Rockwood grades III-V acute acromioclavicular (AC) joint separation. Methods: Patients who underwent graftless or allograft surgery acutely (≤6 weeks from injury) for Rockwood type III-V AC joint separations from 2012 to 2018 were retrospectively reviewed. Clinic notes and operative reports were identified to confirm the surgical technique and presence of complications including revision, infection, and fracture. In addition, postoperative radiographs were assessed to determine any instances of loss of adequate reduction, and several patient-reported outcomes were collected. Results: In total, 115 patients (52 allograft, 63 graftless) were included in this study with a mean follow-up of 3.8 ± 2.5 years. There were no differences between allograft and graftless patients regarding rates of loss of reduction >5 mm (11.1% graftless vs 21.2% allograft), revision (3.2% vs 1.9%), infection (1.6% vs 3.9%), fracture (3.2% vs 7.7%), or total complication (7.9% vs 9.6%) rates (all P > .05). Patient-reported outcome measures also did not significantly differ between groups. Multivariate analysis found that increased time from injury to repair and increased Rockwood injury grade (grades IV and V) were associated with increased CC distance at postoperative follow-up (P = .008, .050, and .047, respectively). Conclusion: Multivariate analysis found that patients who underwent acute AC joint fixation without allograft augmentation had similar functional outcomes, complications, and revision rates compared with patients who underwent AC joint reconstruction with allograft. Level of Evidence: Level III, retrospective comparative study.

A new understanding of radiographic landmarks of the greater trochanter that indicate correct femoral rotation for measurement of femoral offset.

OBJECTIVES: To establish and validate a novel method for aligning femoral rotation to accurately measure femoral offset for preoperative templating and component sizing, and to identify the physical location of two radiographic lines utilized in the described method. MATERIALS AND METHODS: Cadaveric proximal femurs were skeletonized and mounted to a biaxial load frame. Two radiographic lines along the greater trochanter were identified fluoroscopically. The femurs were rotated, and images were taken when the lines appeared superimposed, then in 2-degree increments to 10° of internal and external rotation, and at 30°. Radiographic femoral offset was calculated at each angle, and the maximum and aligned offsets were compared. Bone was removed until the radiographic lines disappeared, then a metal wire was inserted in place of the bone to confirm that the lines reappeared. RESULTS: The physical locations of the radiographic landmarks were on the anterior and posterior aspects of the greater trochanter. The mean true femoral offset was 38.2 mm (range, 30.5-46.3 mm). The mean aligned femoral offset was 37.3 mm (range, 29.3-46.3 mm), a 2.4% underestimation. The mean angle between aligned and true offset was 3.6° of external rotation (range, 10°ER-8°IR). Intra-rater intraclass correlation coefficient was 0.991. CONCLUSION: Alignment of the radiographic lines created by the anterior and posterior aspects of the greater trochanter is a reliable and accurate rotational positioning method for measuring true femoral offset when using plain films or fluoroscopy, which can aid surgeons with preoperative templating and intraoperative component placement for total hip arthroplasty.

Rehabilitation and Return to Sport Criteria Following Ulnar Collateral Ligament Reconstruction: A Systematic Review.

BACKGROUND: Ulnar collateral ligament (UCL) reconstruction (UCLR) is a viable treatment option for patients with UCL insufficiency, especially in the overhead throwing athlete. Within the clinical literature, there is still no universally agreed upon optimal rehabilitation protocol and timing for return to sport (RTS) after UCLR. HYPOTHESIS: There will be significant heterogeneity with respect to RTS criteria after UCLR. Most surgeons will utilize time-based criteria rather than functional or performance-based criteria for RTS after UCLR. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: All level 1 to 4 studies that evaluated UCLR with a minimum 1-year follow-up were eligible for inclusion. Studies lacking explicit RTS criteria, studies that treated UCL injury nonoperatively or by UCL repair, or studies reporting revision UCLR were excluded. Each study was analyzed for methodologic quality, RTS, timeline of RTS, and RTS rate. RESULTS: Overall, 1346 studies were identified, 33 of which met the inclusion criteria. These included 3480 athletes across 21 different sports. All studies reported RTS rates either as overall rates or via the Conway-Jobe scale. Timelines for RTS ranged from 6.5 to 16 months. Early bracing with progressive range of motion (ROM) (93.9%), strengthening (84.8%), and participation in an interval throwing program (81.8%) were the most common parameters emphasized in these rehabilitation protocols. While all studies included at least 1 of 3 metrics for the RTS value assessment, most commonly postoperative rehabilitation (96.97%) and set timing after surgery (96.97%), no article completely defined RTS criteria after UCLR. CONCLUSION: Overall, 93.9% of studies report utilizing bracing with progressive ROM, 84.8% reported strengthening, and 81.8% reported participation in an interval throwing program as rehabilitation parameters after UCLR. In addition, 96.97% reported timing after surgery as a criterion for RTS; however, there is a wide variability within the literature on the recommended time from surgery to return to activity. Future research should focus on developing a comprehensive checklist of functional and performance-based criteria for safe RTS after UCLR.

Return to Sport Rates and Subjective Outcomes Are Similar After Open or Endoscopically Assisted Compartment Release for Chronic Lower-Extremity Exertional Compartment Syndrome.

Purpose: To retrospectively compare return to sport rates and subjective outcomes of patients who underwent open or endoscopic compartment release for the surgical management of chronic exertional compartment syndrome. Methods: This was a retrospective review of patients who underwent lower-extremity fasciotomy for chronic exertional compartment syndrome from June 2012 to June 2020. Eligibility included patients 15 to 45 years of age who identified as an athlete and had at least 6 months of follow-up. Fasciotomies for trauma or infection were excluded. One surgeon exclusively performed each type of surgery. Postoperative outcome measures included the Lower Extremity Functional Scale, the Marx Activity Scale, and a return to play survey. Results: In total, 24 patients (13 endoscopically assisted fasciotomies, 11 open fasciotomies) had a mean follow-up of 3.8 ± 2.1 years; 19 patients returned to their sporting activity. No significant difference existed between return to play rates (P = .630) or return to play times (P = .351). There were no significant differences between the groups in the Lower Extremity Functional Scale score, Marx Activity Scale score, Single Assessment Numeric Evaluation score, pain score at rest, and during sporting activity. Overall satisfaction rates were found to be significantly greater in the endoscopically assisted fasciotomy group (P = .041). Conclusions: In this small sample of heterogenous groups of patients, we found no significant differences in return to sport rates or subjective results after surgery. Patients experienced a high subjective recurrence rate. The endoscopically assisted fasciotomy group reported greater subjective patient satisfaction compared with the open fasciotomy group. Level of Evidence: Level III, comparative study, retrospective.

The Hip Suction Seal, Part II: The Effect of Rim Trimming, Chondrolabral Junction Separation, and Labral Repair/Refixation on Hip Distractive Stability.

BACKGROUND: The acetabular labrum contains free nerve endings, and an unstable labrum can result in increased femoral head movement during hip motion. This can be caused by chondrolabral junction (CLJ) separation, especially in association with pincer-type femoroacetabular impingement, and may contribute to hip pain. HYPOTHESIS: Rim resection alone has no effect on suction seal biomechanics. Further, separation of the CLJ changes hip suction seal biomechanics when compared with those of the native state, whereas repair and refixation with suture anchors restore these biomechanical parameters. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 12 fresh-frozen human cadaveric hips were used in this study. Hips were mounted in a saline bath on a dynamic tensile testing machine and were distracted at a rate of 0.5 mm/s from neutral position. A total of 3 parameters (force, displacement, and intra-articular pressure) were measured throughout testing. Before testing, hips were randomly allocated to 1 of 2 groups: 1 that included the CLJ separation (CLJ Cut group) and 1 that did not (CLJ Intact group). Hips were tested in the following states: (1) native, (2) rim trimming, (3) separated CLJ (CLJ Cut group only), and (4) labral repair/refixation. For each group a linear mixed-effects model was used to compare biomechanical parameters between states. RESULTS: Rim trimming did not affect any suction seal parameters relative to those of the native state. In the CLJ Cut group, no significant difference in distance to break the suction seal was observed for any states compared with that of the native state. In the CLJ Intact group, the distance to break the suction seal was significantly shorter in the labral refixation state (1.8 mm) than the native state (5.6 mm; P = .002). The maximum distraction force (62.1 ± 54.1 N) and the peak negative pressure (-36.6 ± 24.2 kPa) of the labral repair/refixation state were significantly lower than those of the native state in both groups (93.4 ± 41.7 N, P = .01; -60.7 ± 20.4 kPa, P = .02). CONCLUSION: Rim trimming did not change the biomechanical properties of the labral suction seal. Labral refixation resulted in a shorter distance to break the labral suction seal. This indicates that labral mobility is reduced by the labral refixation procedure, which could be beneficial in postoperative pain relief and labral healing. CLINICAL RELEVANCE: The labral refixation reduced labral mobility, which could be beneficial for both pain relief and labral healing to the acetabulum after pincer-type femoroacetabular impingement resection.

The Hip Suction Seal, Part I: The Role of Acetabular Labral Height on Hip Distractive Stability.

BACKGROUND: The acetabular labrum has been found to provide a significant contribution to the distractive stability of the hip. However, the influence of labral height on hip suction seal biomechanics is not known. HYPOTHESIS: The smaller height of acetabular labrum is associated with decreased distractive stability. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 23 fresh-frozen cadaveric hemipelvises were used in this study. Hips with acetabular dysplasia or femoroacetabular impingement-related bony morphologic features, intra-articular pathology, or no measurable suction seal were excluded. Before testing, each specimen's hip capsule was removed, a pressure sensor was placed intra-articularly, and the hip was fixed in a heated saline bath. Labral size was measured by use of a digital caliper. Maximum distraction force, distance to suction seal rupture, and peak negative pressure were recorded while the hip underwent distraction at a rate of 0.5 mm/s. Correlations between factors were analyzed using the Spearman rho, and differences between groups were detected using Mann-Whitney U test. RESULTS: Of 23 hips, 12 satisfied inclusion criteria. The maximum distraction force and peak negative pressure were significantly correlated (R = -0.83; P = .001). Labral height was largely correlated with all suction seal parameters (maximum distraction force, R = 0.69, P = .013; distance to suction seal rupture, R = 0.55, P = .063; peak negative pressure, R = -0.62, P = .031). Labral height less than 6 mm was observed in 5 hips, with a mean height of 6.48 mm (SD, 2.65 mm; range, 2.62-11.90 mm; 95% CI, 4.80-8.17 mm). Compared with the 7 hips with larger labra (>6 mm), the hips with smaller labra had significantly shorter distance to suction seal rupture (median, 2.3 vs 7.2 mm; P = .010) and significantly decreased peak negative pressure (median, -59.3 vs -66.9 kPa; P = .048). CONCLUSION: Smaller height (<6 mm) of the acetabular labrum was significantly associated with decreased distance to suction seal rupture and decreased peak negative pressure. A new strategy to increase the size of the labrum, such as labral augmentation, could be justified for patients with smaller labra in order to optimize the hip suction seal. CLINICAL RELEVANCE: The height of the acetabular labrum is correlated with hip suction seal biomechanics. Further studies are required to identify the clinical effects of labral height on hip stability.

Variations in Blood Supply From Proximal to Distal in the Ulnar Collateral Ligament of the Elbow: A Qualitative Descriptive Cadaveric Study.

BACKGROUND: The vascular supply of the ulnar collateral ligament (UCL) is unknown. Previous studies reported varying success in return-to-play rates after nonoperative management of partial UCL tears and suggested a varying healing capacity as possibly related to the location of the UCL injury. PURPOSE: To analyze the macroscopic vascular anatomy of the UCL of the elbow. STUDY DESIGN: Descriptive laboratory study. METHODS: Eighteen fresh-frozen male cadaveric elbows from 9 donors were sharply dissected 15 cm proximal to the medial epicondyle. Sixty milliliters of India ink was injected through the brachial artery of each elbow. Arms were then frozen at -10°C, radial side down, in 15° to 20° of elbow flexion. A band saw was used to section the frozen elbows into 5-mm coronal or sagittal sections. Sections were cleared for visualization with the modified Spalteholz technique. Images of the specimens were taken, and qualitative description of UCL vascularity was undertaken. RESULTS: The authors consistently found a dense blood supply to the proximal UCL, while the distal UCL was hypovascular. They also observed a possible osseous contribution to the proximal UCL from the medial epicondyle in addition to an artery from the flexor/pronator musculature that consistently appeared to provide vascularity to the proximal UCL. The degree of vascular penetration from proximal to distal in the UCL ranged from 39% to 68% of the overall UCL length, with a 49% mean length of vascular penetration of the UCL. CONCLUSION: This study found a difference in the vascular supply of the UCL. The proximal UCL was well vascularized, while the distal UCL was hypovascular. This difference in vascular supply may be a factor in the differential healing capacities of the UCL based on the location of injury. CLINICAL RELEVANCE: An improved understanding of the macroscopic vascular supply of the UCL may aid in the clinical management of partial UCL tears and suggests an indication for these treatments with respect to location of UCL injuries.

Tibial Slope and Its Effect on Force in Anterior Cruciate Ligament Grafts: Anterior Cruciate Ligament Force Increases Linearly as Posterior Tibial Slope Increases.

BACKGROUND: Previous work has reported that increased tibial slope is directly correlated with increased anterior tibial translation, possibly predisposing patients to higher rates of anterior cruciate ligament (ACL) tears and causing higher rates of ACL graft failures over the long term. However, the effect of changes in sagittal plane tibial slope on ACL reconstruction (ACLR) graft force has not been well defined. PURPOSE/HYPOTHESIS: The purpose of this study was to quantify the effect of changes in sagittal plane tibial slope on ACLR graft force at varying knee flexion angles. Our null hypothesis was that changing the sagittal plane tibial slope would not affect force on the ACL graft. STUDY DESIGN: Controlled laboratory study. METHODS: Ten male fresh-frozen cadaveric knees had a posterior tibial osteotomy performed and an external fixator placed for testing and accurate slope adjustment. Following ACLR, specimens were compressed with a 200-N axial load at flexion angles of 0°, 15°, 30°, 45°, and 60°, and the graft loads were recorded through a force transducer clamped to the graft. Tibial slope was varied between -2° and 20° of posterior slope at 2° increments under these test conditions. RESULTS: ACL graft force in the loaded testing state increased linearly as slope increased. This effect was independent of flexion angle. The final model utilized a 2-factor linear mixed-effects regression model and noted a significant, highly positive, and linear relationship between tibial slope and ACL graft force in axially loaded knees at all flexion angles tested (slope coefficient = 0.92, SE = 0.08, P < .001). Significantly higher graft force was also observed at 0° of flexion as compared with all other flexion angles for the loaded condition (all P < .001). CONCLUSION: The authors found that tibial slope had a strong linear relationship to the amount of graft force experienced by an ACL graft in axially loaded knees. Thus, a flatter tibial slope had significantly less loading of ACL grafts, while steeper slopes increased ACL graft loading. Our biomechanical findings support recent clinical evidence of increased ACL graft failure with steeper tibial slope secondary to increased graft loading. CLINICAL RELEVANCE: Evaluation of the effect of increasing tibial slope on ACL graft force can guide surgeons when deciding if a slope-decreasing proximal tibial osteotomy should be performed before a revision ACLR. Overall, as slope increases, ACL graft force increases, and in our study, flatter slopes had lower ACL graft forces and were protective of the ACLR graft.