Editorial Commentary: Endoscopic Repair of Abductor Tendon Tears Results in Variable Patient Reported Outcomes and Generally Good to Excellent Results.

Abductor tendon pathology is fairly common, with up to a 25% incidence in patients having total hip arthroplasty and 30% having hip arthroscopy. A systematic review of endoscopic abductor tendon repair demonstrated that as few as 41% of patients with endoscopic repair of abductor tendon tears achieve a patient acceptable satisfactory state, but a major limitation of systematic reviews is extreme heterogeneity between included studies. Surgical techniques and skills differ, as do tear severity and confounding pathology such as labral tears. Another limitation is a focus on patient-reported outcome measures (PROMs). PROMs are important (we prefer happy patients with poor healing to unhappy patients with healed repairs), but PROMs are also "subjective," and different cohorts of patients in different studies from different locations may have different perceptions or goals with regard to pain and function. As surgeons, we are able to observe gait, strength, and, with advanced imaging when indicated or for research purposes, healing. These, combined with PROMs, influence overall assessment of outcome. Experience and review of the literature show that endoscopic surgical repair of abductor tendon tears generally shows good or excellent results. If a patient has significant pain improvement and objectively improved gait, a calculation of an outcome threshold based on a subjective survey may not tell the full story.

Editorial Commentary: Indications for Acetabular Labral Debridement Versus Repair and Reconstruction: There is Still a Role for Selective Labral Debridement.

Not all acetabular labral tears, tissue quality, and size are the same. There is still a role for selective debridement of the acetabular labrum when stable, functional labral tissue remains. An unstable labrum that appears very different than the rest of the labrum is an easy target for repair. Tears requiring resection require graft augmentation or reconstruction.

Editorial Commentary: The Optimal Nerve Block for Hip Arthroscopy Is Undetermined.

The optimal nerve block to help reduce pain after hip arthroscopy is undetermined. The fascia iliaca block was en vogue but may result in weakness, neuropathy, and equivocal pain outcomes. Other options include blocks to the femoral nerve, the lumbar plexus, the quadratus lumborum, and, more recently, the pericapsular nerve group block (PENG), in which ultrasound guidance allows injection under the iliopsoas muscle to affect the accessory obturator nerve and the articular branches of the femoral nerve. PENG block should not result in weakness, but weakness has been reported after PENG block for total hip arthroplasty, and falls could be a risk and a concern. The arthroplasty literature also suggests the PENG block adds little benefit to intra-articular injection beyond the recovery room and is comparable with a fascia iliac block. Perhaps the PENG block could show benefit in select cases such as for severe postoperative pain or in patients with anticipated pain control challenges. Until an ideal block for hip arthroscopy is determined, a patient tailored approach is indicated.

Editorial Commentary: Revision Hip Arthroscopy in Patients Older Than 40 Has a Higher Rate of Conversion to Total Hip Arthroplasty-Get It Right the First Time, and the Second.

Getting hip arthroscopy right the first time is critical to the overall patient outcome. This involves proper patient selection, with avoidance of arthritis, understanding the pathology of each hip, and properly executing the surgery. Care must be taken to restore labral function and preserve capsule function while accurately resecting pincer or cam impingement. While good results can be achieved in patients older than 40 years of age, an opportunity exists for improved optimization of clinical outcomes. Moreover, revision hip arthroscopy in patients older than 40 years of age has a higher rate of conversion to total hip arthroplasty. Again, get it right the first time, and carefully consider indications for revision hip arthroscopy in patients older than 40 years of age if there is a second time.

Editorial Commentary: The Everted Acetabular Labrum. It Is Not Just a Small Labrum.

Everted, hypoplastic acetabular labra represent a variant of acetabular rim development. It is important to be able to recognize this pathology on magnetic resonance imaging and at the time of hip arthroscopy. Proper intraoperative identification of this variant that does not make contact with the femoral head is critical to being able to successfully restore this contact, often through labral advancement, acetabuloplasty of the abnormal rim development, and occasionally labral augmentation. A broad awareness among hip arthroscopy surgeons of this topic will lead to improved clinical outcomes after hip arthroscopy for a challenging cohort.

Editorial Commentary: Large Heterogeneity of Minimal Clinically Important Difference Utilization in Hip Arthroscopy Studies: Where Do We Go From Here?

The minimal clinically important difference is a relatively new method to evaluate outcomes after surgery, defined as the lowest value of change in the outcome score that results in a perceived clinical improvement. There is no clear delineation of use for this metric, resulting in a heterogeneous application in hip arthroscopy research, making comparisons with other studies difficult. Cohort-specific values calculated using an anchor-based method are best.

Editorial Commentary: Labral Calcification in the Setting of Femoroacetabular Impingement Syndrome: The Gratification of Eradication and Treatment of the Problem.

Acetabular labral calcifications are occasionally encountered during hip arthroscopy for labral tears and femoroacetabular impingement. Clinical outcomes after removal of this calcification and repair of labral tearing have been shown to be good. Since these are found in asymptomatic patients, the labral repair and treatment of femoroacetabular impingement seem to be more important than removal of the calcification. However, amorphous calcium deposits need to be distinguished from the more serious conditions of labral ossification or rim fractures, which require significant preoperative planning and patient counseling. Labral reconstruction or rim fixation will alter the surgical procedure and potentially the postoperative rehabilitation.

Editorial Commentary: Microinstability After Cam Osteochondroplasty Results From Over-Resection-Everything in Moderation.

Cam impingement is one of the most common pathologies treated with hip arthroscopy. While it is a common treatment, it can be difficult to achieve the perfect osteochondroplasty, one that neither over- nor under-resects the head-neck junction. Clinical studies and now biomechanical analysis show over-resection of cam lesions can result in inferior clinical outcomes from microinstability.

Editorial Commentary: Hip Joint Space as a Predictor of Cartilage Pathology: A Basic Tool for a Complex Task.

Predicting articular cartilage pathology in the hip with radiographic joint space has been unreliable for patients having joint spaces >2 mm in width. Joint space width is a tool that can be used, but with some limitation. Other methods of investigation such as magnetic resonance imaging should be used in conjunction with radiographic joint space.

Editorial Commentary: The Hip Capsule: To Close or Not to Close? Is That Still the Question?

The question of capsule closure or no closure after hip arthroscopy remains controversial as we try to decipher best practice and which patients should and should not have a repair. Closure seems of particular importance in younger patients and with larger capsulotomies. In my practice, I routinely repair the capsule after hip arthroscopy, except in patients with significant stiffness. Capsule repair may not be vital in some patients, as a smaller capsulotomy could sometimes heal on its own, but my patients and I certainly do not want to learn the hard way.

Editorial Commentary: Hip Arthroscopy With Concomitant Periacetabular Osteotomy: Teamwork Makes This Dream Work.

Arthroscopy provides a powerful tool to successfully treat intra-articular hip pathology secondary to dysplasia while improving the bony coverage/alignment with periacetabular osteotomy; a concept no different than high tibial osteotomy. Through a specialized team approach, all relevant pathology can be addressed and successful outcomes achieved.

Editorial Commentary: Fluid Extravasation in Hip Arthroscopy-A Tough Case Just Got Much Worse.

Hip arthroscopy has its complications like any other surgery, but abdominal compartment syndrome is unique to the hip and is a complication with devastating consequences. Avoidance is the rule.

Endoscopic Sciatic Nerve Decompression in the Prone Position-An Ischial-Based Approach.

Deep gluteal syndrome is described as sciatic nerve entrapment in the region deep to the gluteus maximus muscle. The entrapment can occur from the piriformis muscle, fibrous bands, blood vessels, and hamstrings. Good clinical outcomes have been shown in patients treated by open and endoscopic means. Sciatic nerve decompression with or without piriformis release provides a surgical solution to a difficult diagnostic and therapeutic problem. Previous techniques have used open methods that can now performed endoscopically. The technique of an endoscopic approach to sciatic nerve decompression in the prone position is described as well as its advantages and common findings. Through this ischial-based approach, a familiar anatomy is seen and areas of sciatic nerve entrapment can be readily identified and safely decompressed.

Chondral Lesions of the Hip.

The treatment of chondral hip injuries is challenging. However, for young patients with hip disorders, orthopedic surgeons now have the opportunity to intervene early in the development of debilitating joint disease. As understanding of the hip joint continues to evolve, more effective treatment strategies are emerging. There are several reportedly successful options for surgical treatment. This article reviews the clinical presentation of chondral injuries and the surgical modalities, arthroscopic and open, available to treat them.

Supine and Standing AP Pelvis Radiographs in the Evaluation of Pincer Femoroacetabular Impingement.

BACKGROUND: Pelvic tilt can affect the presence of the ischial spine sign and crossover sign. Numerous studies of pelvic tilt on radiographic measurements of pincer impingement have shown that increasing anterior tilt is associated with more radiographic signs of pincer impingement. However, to our knowledge, no study has directly compared supine and standing plain radiographs in patients with respect to lateral center-edge (LCE) angle, acetabular inclination, crossover sign, and ischial spine sign. QUESTIONS/PURPOSES: The purpose of this study was to evaluate the differences in supine and standing AP pelvis radiographs as they relate to the radiographic parameters of pincer impingement in an adult population evaluated for femoroacetabular impingement, specifically intrapelvic distances (sacrococcygeal to symphysis [SC-S] and coccyx tip to symphysis [T-S]), crossover sign (presence and percentage), LCE angle, inclination, and ischial spine sign. METHODS: Between August 2013 and June 2014, we obtained supine and standing radiographs for all new patients younger than 60 years who were evaluated for hip pain, when the diagnosis of fracture was not being considered; these formed the basis of this retrospective study. Patients were excluded if they had arthritis (Tönnis grade ≥ 2), lumbar fusion, previous hip surgery, or malrotated films. Forty-six hips, symptomatic side, met the inclusion criteria (age of patients, 33 ± 14 years; 13 males, 33 females). Radiographic data that were collected included SC-S distance, T-S distance, LCE angle, acetabular inclination, presence and percentage of crossover sign, and presence of ischial spine sign. A paired t-test was used to compare continuous variables and chi-square test was used for categorical variables. Two independent readers performed measurements. RESULTS: From supine to standing films, the T-S distance decreased from 19 ± 18 mm to 6 ± 19 mm (p < 0.001), and SC-S distance decreased from 47 ± 19 mm to 32 ± 20 mm (p < 0.001), indicating less pelvic tilt in the standing position. The number of hips that had crossover signs decreased from supine (n = 18, 39%) to standing (n = 9, 20%) (p = 0.039). The amount of crossover decreased from 23% ± 10% to 11% ±13% (p < 0.001). LCE angle did not change (27° ± 7° to 27° ± 8°) (p = 0.64) and inclination angle increased by a small amount (4.2° ± 5° to 5.3° ± 5°) (p = 0.002). The ischial spine sign decreased from supine (n = 20, 43%) to standing (n = 7, 15%) position (p = 0.003). CONCLUSIONS: There is a decrease in the amount of pelvic tilt on standing AP pelvis radiographs resulting in a decrease in the incidence and amount of crossover sign and ischial spine sign, and a small increase in inclination. Standing radiographs should be the standard in evaluation of nonarthritic hip pain, specifically pincer femoroacetabular impingement. Surgeons should use caution in interpreting supine AP radiographs in the evaluation of pincer impingement, specifically the crossover sign. LEVEL OF EVIDENCE: Level III, diagnostic study.

Biomechanical Effects of Capsular Shift in the Treatment of Hip Microinstability: Creation and Testing of a Novel Hip Instability Model.

BACKGROUND: A capsular shift procedure has been described for the treatment of hip instability; however, the biomechanical effects of such a shift are unknown. PURPOSE: To create a cadaveric model of hip capsule laxity and evaluate the biomechanical effects of a capsular shift used to treat hip instability on this model. STUDY DESIGN: Controlled laboratory study. METHODS: Eight cadaveric hips with an average age of 58.5 years were tested with a custom hip testing system in 6 conditions: intact, vented, instability, capsulotomy, side-to-side repair, and capsular shift. To create the hip model, the capsule was stretched in extension under 35 N·m of torque for 1 hour in neutral rotation. Measurements included internal and external rotation with 1.5 N·m of torque at 5 positions: 5° of extension and 0°, 15°, 30°, and 45° of flexion for each of the above conditions. The degree of maximum extension with 5 N·m of torque and the amount of femoral distraction with 40 N and 80 N of force were measured. Statistical analysis was performed by use of repeated-measures analysis of variance with Tukey post hoc analysis. RESULTS: The instability state significantly increased internal rotation at all flexion angles and increased distraction compared with the intact state. The capsulotomy condition resulted in significantly increased external rotation and internal rotation at all positions, increased distraction, and maximum extension compared with the intact state. The side-to-side repair condition restored internal rotation back to the instability state but not to the intact state at 5° of extension and 0° of flexion. The capsular shift state significantly decreased internal rotation compared with the instability state at 5° of extension and 0° and 15° of flexion. The capsular shift and side-to-side repair conditions had similar effects on external rotation at all flexion-extension positions. The capsular shift state decreased distraction and maximum extension compared with the instability state, but the side-to-side repair state did not. CONCLUSION: The hip capsular instability model was shown to have significantly greater total range of motion, external rotation, and extension compared with the intact condition. The greatest effects of capsular shift are seen with internal rotation, maximum extension, and distraction, with minimal effect on external rotation compared with the side-to side repair state. CLINICAL RELEVANCE: The biomechanical effects of the capsular shift procedure indicate that it can be used to treat hip capsular laxity by decreasing extension and distraction with minimal effect on external rotation.

Biomechanical differences of the anterior and posterior bands of the ulnar collateral ligament of the elbow.

PURPOSE: The main purpose of this study was to examine the functional characteristics of the anterior and posterior bands of the anterior bundle of the ulnar collateral ligament (UCL). METHODS: Six cadaveric elbows were tested using a digital tracking system to measure the strain in the anterior band and posterior band of the anterior bundle of the UCL throughout a flexion/extension arc. The specimens were then placed in an Instron materials testing machine and loaded to failure to determine yield load and ultimate load of the UCL. RESULTS: The posterior band showed a linear increase in strain with increasing degrees of elbow flexion while the anterior band showed minimal change in strain throughout. The bands showed similar strain at yield load and ultimate load, demonstrating similar intrinsic properties. CONCLUSION: The anterior band of the anterior bundle of the UCL shows an isometric strain pattern through elbow range of motion, while the posterior band shows an increasing strain pattern in higher degrees of elbow flexion. Both bands show similar strain in a load to failure model, indicating insertion point, not intrinsic differences, of the bands determine the function of the anterior bundle of the UCL. This demonstrates a biomechanical rationale for UCL reconstructions using single point anatomical insertion points.

Leg-Length Discrepancy After Total Hip Arthroplasty: Comparison of Robot-Assisted Posterior, Fluoroscopy-Guided Anterior, and Conventional Posterior Approaches.

Total hip arthroplasty (THA) effectively provides adequate pain relief and good long-term outcomes in patients with hip osteoarthritis. However, leg-length discrepancy (LLD) remains the most common cause of patient dissatisfaction and malpractice litigation in hip arthroplasty. We conducted a study to compare LLD in patients who underwent THA performed with a robot-assisted posterior approach (RTHA), a fluoroscopy-guided anterior approach (ATHA), or a conventional posterior approach (PTHA). We reviewed all RTHA, ATHA, and PTHA cases performed by Dr. Domb between September 2008 and December 2012. Patients included in the study had a primary diagnosis of hip osteoarthritis and proper postoperative anteroposterior pelvis radiographs available. Two blinded observers calibrated and measured all radiographs twice. After exclusions, 67 RTHA, 29 ATHA, and 59 PTHA cases remained in the study. There were strong interobserver and intraobserver correlations for all LLD measurements (r > 0.9; P < .001). Mean (SD) LLD was 2.7 (1.8) mm (95% CI, 2.3-3.2) in the RTHA group, 1.8 (1.6) mm (95% CI, 1.2-2.4) in the ATHA group, and 1.9 (1.6) mm (95% CI, 1.5-2.4) in the PTHA group (P = .01). When LLD of more than 3 mm was set as an outlier, percentage of outliers was 37.3% (RTHA), 17.2% (ATHA), and 22% (PTHA) (P = .06-.78). When LLD of more than 5 mm was set as an outlier, percentage of outliers was 10.4% (RTHA), 6.9% (ATHA), and 8.5% (PTHA) (P = .72 to > .99). No patient in any group had LLD of 10 mm or more. RTHA, ATHA, and PTHA did not differ in obtaining minimal LLD. All 3 techniques are effective in achieving accuracy in LLD.

Acetabular Labral Base Repair Versus Circumferential Suture Repair: A Matched-Paired Comparison of Clinical Outcomes.

PURPOSE: To determine whether an acetabular labral repair technique would be superior to another repair technique based on clinical outcomes measured by patient-reported outcome (PRO) scores. METHODS: We identified 465 patients who underwent labral base repair or circumferential suture repair from February 2008 to February 2012. The type of repair performed was based on labral size and tear type. The 2 groups were pair matched for age within 5 years, sex, crossover sign within 15%, coxa profunda, Workers' Compensation status, and microfracture (femur, acetabulum, or none). Data were prospectively collected and retrospectively reviewed. PROs included a visual analog scale score and the modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score-Activities of Daily Living, and Hip Outcome Score-Sports-Specific Subscale. RESULTS: One hundred ten patients met the inclusion criteria for labral base repair and were pair matched on a 1:1 basis with 110 patients who underwent circumferential suture repair. The mean follow-up period was 30 months for both groups, with a range of 19.2 to 60 months for the labral base repair group and 19.2 to 67 months for the circumferential suture repair group. Radiographic data were similar between groups with respect to the lateral center-edge angle (P = .906), acetabular inclination (P = .329), anterior center-edge angle (P = .208), alpha angle (P = .387), and joint space width (P = .388). All preoperative PRO scores were statistically similar. Both groups showed significant improvements in all PROs. There were no statistical differences in postoperative PRO scores at latest follow-up (modified Harris Hip Score, P = .215; Hip Outcome Score-Activities of Daily Living, P = .839; Hip Outcome Score-Sports-Specific Subscale, P = .561; Non-Arthritic Hip Score, P = .333; visual analog scale score, P = .373; and satisfaction, P = .483). There were similar rates of revision (n = 10 for both groups) and conversion to arthroplasty (n = 2 for both groups). CONCLUSIONS: On the basis of PRO scores at 2 years' follow-up, there is no difference in outcomes based on the type of labral repair performed. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Predictive value of robotic-assisted total hip arthroplasty.

Acetabular cup positioning, leg-length discrepancy, and global offset are important parameters associated with outcomes following total hip arthroplasty (THA). Deviation from an accepted range of values can lead to significant complications, including dislocation, leg-length discrepancy, impingement, accelerated bearing surface wear, and revisions. The purpose of this study was to assess whether robotic-assisted THA was reliable in predicting radiographic measurements of cup inclination and anteversion, leg-length change, and global offset change. All 61 robotic-assisted THAs that met the inclusion and exclusion criteria were performed by a single surgeon through a mini-posterior approach. Data provided by the robot were collected prospectively, and radiographic data were collected retrospectively by 2 blinded independent reviewers. The cohort in this study consisted of 27 male and 34 female patients, with an average age of 60.5 years. A strong inter- and intraobserver correlation was found for the radiographic measurements of cup inclination, cup anteversion, leg-length discrepancy, and global offset (r>0.8 with P<.001 for all). Ninety-six point seven percent of robotic-measured inclination angles and 98.4% of robotic-measured anteversion angles were within 10° of radiographic measurements. One hundred percent of robotic-measured leg-length change and 91.8% of robotic-measured global offset change were within 10 mm of radiographic measurements. Robotic-assisted THA showed good predictive value for cup inclination and anteversion angles and measurements of leg-length change and global offset change done postoperatively on plain radiographs. Further refinement of the robotic system would make it more accurate in predicting the postoperative parameters mentioned.