Hip microinstability and its association with femoroacetabular impingement: A scoping review.

Introduction: Hip microinstability has become a recognized cause of non-arthritic hip pain and disability in young patients. However, its pathophysiology remains unclear. We want to (1) present an overview of the evidence of hip microinstability and of its association with femoroacetabular impingement (FAI), (2) map out the type of evidence available, and (3) make recommendations for future research. Methods: A deductive analysis and extraction method was used to extract information. In addition, diagnostic accuracy statistics were extracted or calculated. Results: Of the 2,808 identified records, 123 were eligible for inclusion. Different definitions for microinstability exist. A standardized terminology and clear diagnostic criteria are lacking. FAI and microinstability may be associated and may aggravate each other. Conservative treatment strategies for FAI and microinstability are similar. The reported prevalence of microinstability in combination with FAI ranges from 21% to 42% in adults undergoing hip arthroscopy or magnetic resonance arthrography (MRA) of the hip. Conclusion: Hip microinstability and FAI may be associated, occur together, or exacerbate each other. To better address this topic, a standardized terminology for microinstability is essential. Achieving consensus on physical examination and diagnosis is also necessary. Initial efforts to establish uniform diagnostic criteria have been made, but further work is needed. Specifically, randomized controlled trials are required to evaluate the effectiveness of training programmes aimed at reducing symptoms in individuals with microinstability, with or without FAI. Such studies will enable clinicians to manage microinstability with greater confidence within this context.

Assessment of function and muscle strength after endoscopic iliopsoas tenotomy to treat iliopsoas impingement after total hip arthroplasty.

PURPOSE: The objective of this study was to evaluate the functional outcome during follow-up (FU) after endoscopic tenotomy for iliopsoas (IP)-cup impingement and to quantitatively analyze the hip flexion strength. METHODS: This was a monocentric, retrospective cohort study of a single surgeon series. Functional assessment was based on the modified Harris score, the Oxford score and the visual analog scale score. Strength was measured with a handheld dynamometer in the sitting and lying position. RESULTS: Thirty-six IP tenotomies for cup impingement were performed between May 2013 and November 2021. Seven (19%) patients were lost to FU. At the time of tenotomy, the mean (standard deviation) age was 62,6 (12,2) and BMI was 26,5 (4,1). The mean FU time after tenotomy to the last FU was 3,6 (0,8) years. All three outcome scores improved from preoperatively to six months postoperatively (p < 0.001). There were no significant change from six months to last FU. The minimal clinically important difference (MCID) of the modified Harris score was set at 25. 20 (69%) patients had values that exceeded the threshold at one month and six months and neutral 19 (65.5%) had values that exceeded the threshold at the last FU. The limp symmetry index concerning hip flexion strength was 63% at 90° and 40% at 30° at the last FU. CONCLUSION: Most patients significantly improved their outcome scores after endoscopic iliopsoas tenotomy, with results remaining consistently stable over time. Despite a significant loss in hip flexion strength, the majority of patients did not report any impairment of their quality of life. STUDY DESIGN: Level III, Retrospective cohort study.

Pre-operative gait kinematics and kinetics do not change following surgery in adolescent patients with femoroacetabular impingement.

BACKGROUND: Femoroacetabular impingement (FAI) is a condition where the femoral head-neck junction collides with the acetabulum. Open or arthroscopic treatment of FAI aims to increase hip motion while reducing impingement during passive or dynamic movements. RESEARCH QUESTION: What are the biomechanical characteristics of the hip and pelvis in adolescents and young adults diagnosed with FAI syndrome 1) pre-operatively compared to controls and 2) pre- to post-operatively? METHODS: 43 patients with FAI and 43 controls were included in the study. All patients with FAI had cam deformities and underwent unilateral hip preservation surgery (either open or arthroscopic). Pre- and post-operative imaging, patient-reported outcomes, and gait analysis were performed. Joint angles and internal joint moments were evaluated with an emphasis on the pelvis and hip. A comparative analysis was conducted to evaluate the gait patterns before and after surgical treatment, as well as to compare pre-operative gait patterns to a control group. RESULTS: 43 patients with FAI (28 female, 16.5 ± 1.5 yrs) and 43 controls (28 female, 16.0 ± 1.5 yrs) were included. Pre-operative patients with FAI had decreased stride length and walking speed compared to controls, with no significant change following surgery. There were no differences in sagittal and coronal plane hip and pelvis kinematics comparing pre- to post-operative and pre-operative to controls. Pre-operatively, differences in internal hip rotation angle (pre: 3.3˚, post: 3.9˚, controls: 7.7˚) and hip extensor moment (pre: 0.121, post: 0.090, controls: 0.334 Nm/kg) were observed compared to controls with no significant changes observed following surgery. SIGNIFICANCE: Compensatory movement strategies in pelvic and hip motion are evident during gait in patients with FAI, particularly in the sagittal and transverse planes. These strategies remained consistent two years post-surgery. While surgery improved radiographic measures and patient-reported outcomes, gait did not elicit biomechanical changes following surgical treatment.

Soft Tissue Cam Impingement in Adolescents: MRI Reveals Impingement Lesions Underappreciated on Radiographs.

BACKGROUND: Femoroacetabular impingement (FAI) has been described as repetitive and abnormal contact between a structurally abnormal proximal femur (cam) and/or acetabulum (pincer), occurring during the terminal range of motion of the hip. While cam and pincer lesions have traditionally been defined as osseous abnormalities, there may be a subset of adolescent patients whose impingement is primarily soft tissue (nonosseous). The existence of a nonosseous cam lesion in adolescents with FAI has not been well described. PURPOSE: To identify and characterize a series of adolescent patients with nonosseous (soft cam) FAI identified on magnetic resonance imaging (MRI) and compare these patients' clinical presentation and outcome with those of a cohort with primary osseous cam FAI in the same age group. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A prospective institutional registry of patients with symptomatic FAI was reviewed. Patients were included if they had an MRI scan and a lateral radiograph of the hip (45° Dunn or frog) at a baseline visit. On MRI, the anterolateral femoral head was evaluated using radial, coronal, sagittal, or axial oblique sequences. A soft cam lesion was identified by the presence of soft tissue thickening of ≥2 mm at the anterolateral femoral head-neck junction. An alpha angle was measured on MRI scans and radiographs when a lesion was identified. The cohort with soft cam lesions was reviewed and findings and outcomes were compared with those of a cohort with osseous cam lesions. Continuous variables were first examined for normality, and then nonparametric tests-such as the Kruskal-Wallis test-were considered. The change between pre- and postoperative patient-reported outcomes (PROs) was described by mean and standard deviation and evaluated with an independent-samples t test. RESULTS: A total of 31 (9.3%) of 332 hips (mean age, 16.4 years [range 13.1-19.6 years]; women, 83.9%) were identified with a soft tissue impingment lesion on MRI at the femoral head-neck junction between the 12 and 3 o'clock positions. These lesions demonstrated a thickened perichondral ring (71%), periosteal thickening (26%), or a cartilaginous epiphyseal extension (3%). The mean alpha angle on MRI was greater than on radiographs (63.5°± 7.9° vs 51.3°± 7.9°; P < .0001). A total of 22 patients (71%) with soft impingement underwent hip preservation surgery. When compared with patients in the osseous cohort who also underwent surgical management, both groups showed similar significant improvements from pre- to postoperatively (soft: modified Harris Hip Score [mHHS], 26.9 ± 18.2; Hip disability and Osteoarthritis Outcome Score [HOOS], 31.4 ± 22.9; osseous: mHHS, 22.8 ± 20.8; HOOS, 27.4 ± 20.1; P < .0001), with a mean follow-up of 3.4 years (range, 1-7 years) in the soft cam cohort and 3 years (1-10.1 years) in the osseous cam cohort. CONCLUSION: Clinicians should be aware of nonosseous or soft cam lesions that cause impingement in adolescent patients without an obvious osseous cam on radiographs. MRI is required to detect these soft cam lesions. When nonoperative treatment fails, the PROs in these patients after operative management are comparable with those in patients with osseous cam lesions. Further research is needed to determine whether the soft cam precedes an osseous cam or whether it is a separate entity.

Clinical Commentary: A Criteria-Based Testing Protocol for Return to Sport Post Hip Arthroscopy for Impingement.

Overall, 84%-87% of athletes will return to sport following hip arthroscopy; however, some literature suggests that only 57% of athletes return to their preinjury level, and only 16.9% report optimal performance. This discrepancy may be due to a lack of consistency within the definition of return to sport as well as a lack of consistency within rehabilitation programs when determining return to sport readiness. Athletes who are returning to sport must demonstrate adequate range of motion, strength, and the ability to perform multi-directional movements without the risk of reinjury. There has yet to be a comprehensive, criteria-based, return to sport testing protocol that utilizes objective measures to ensure athletes are ready for return to sport. The goal of the authors was to create a criteria-based testing protocol for return to sport following hip arthroscopy utilizing components best supported in the literature. The following parameters were identified as key areas to assess for within a return to sport testing protocol: range of motion, strength, functional testing, self-reported outcomes including psychological readiness and time. The purpose of this clinical commentary is to propose a criteria-based testing protocol to be used following hip arthroscopy for impingement from early rehabilitation through return to previous level of sport. Criteria are presented clearly to promote objective progression through rehabilitation while still being mindful of the biological healing time required for safe and efficient progression. It is the authors' hope that in identifying and establishing a criteria-based testing protocol a higher percentage of athletes will be able to return to sport. Level of Evidence: 5.

Non-operative Management and Outcomes of Femoroacetabular Impingement Syndrome.

PURPOSE: To serve as a guide for non-operative physicians in the management of femoroacetabular impingement syndrome and provide an algorithm as to when to refer patients for potential surgical management. RECENT FINDINGS: Supervised physical therapy programs that focus on active strengthening and core strengthening are more effective than unsupervised, passive, and non-core-focused programs. There is promising evidence for the use of intra-articular hyaluronic acid and PRP as adjunct treatment options. Recent systematic reviews and meta-analyses have found that in young active patients, hip arthroscopy demonstrates improved short-term outcomes over physical therapy. The decision for the management of FAIS is complex and should be specific to each patient. Consideration of the patient's age, timing to return to sport, longevity of treatment, hip morphology, and degree of cartilage degeneration is required to make an informed decision in the treatment of these patients.

Posterior Hip Impingement at Maximal Hip Extension in Female Patients With Increased Femoral Version or Increased McKibbin Index and Its Effect on Sports Performance.

Background: The location of posterior hip impingement at maximal extension in patients with posterior femoroacetabular impingement (FAI) is unclear. Purpose: To investigate the frequency and area of impingement at maximal hip extension and at 10° and 20° of extension in female patients with increased femoral version (FV) and posterior hip pain. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Osseous patient-specific 3-dimensional (3D) models were generated of 50 hips (37 female patients, 3D computed tomography) with a positive posterior impingement test and increased FV (defined as >35°). The McKibbin index (combined version) was calculated as the sum of FV and acetabular version (AV). Subgroups of patients with an increased McKibbin index >70° (24 hips) and FV >50° (20 hips) were analyzed. A control group of female participants (10 hips) had normal FV, normal AV, and no valgus deformity (neck-shaft angle, <139°). Validated 3D collision detection software was used for simulation of osseous impingement-free hip extension (no rotation). Results: The mean impingement-free maximal hip extension was significantly lower in patients with FV >35° compared with the control group (15° ± 15° vs 55° ± 19°; P < .001). At maximal hip extension, 78% of patients with FV >35° had osseous posterior extra-articular ischiofemoral hip impingement. At 20° of extension, the frequency of posterior extra-articular ischiofemoral impingement was significantly higher for patients with a McKibbin index >70° (83%) and for patients with FV >35° (76%) than for controls (0%) (P < .001 for both). There was a significant correlation between maximal extension (no rotation) and FV (r = 0.46; P < .001) as well as between impingement area at 20° of extension (external rotation [ER], 0°) and McKibbin index (0.61; P < .001). Impingement area at 20° of extension (ER, 0°) was significantly larger for patients with McKibbin index >70° versus <70° (251 vs 44 mm2; P = .001). Conclusion: The limited hip extension found in our study could theoretically affect the performance of sports activities such as running, ballet dancing, or lunges. Therefore, although not examined directly in this study, these activities are not advisable for these patients. Preoperative evaluation of FV and the McKibbin index is important in female patients with posterior hip pain before hip preservation surgery (eg, hip arthroscopy).

Postoperative Rehabilitation for Arthroscopic Management of Femoroacetabular Impingement Syndrome: a Contemporary Review.

PURPOSE OF REVIEW: Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain that may potentially lead to osteoarthritis. Operative management of FAIS seeks to arthroscopically reshape the abnormal hip morphology and repair the labrum. For rehabilitation following operative management, a structured physical therapy program is unanimously recommended for the patient to return to their previous level of physical activity. Yet, despite this unanimous recommendation, significant heterogeneity exists among the current recommendations for postoperative physical therapy programs. RECENT FINDINGS: A four-phase postoperative physical therapy protocol is favored among current literature, with each phase being comprised of its own goals, restrictions, precautions, and rehabilitation techniques. Phase 1 aims to protect the integrity of the surgically repaired tissues, reduce pain and inflammation, and regain ~ 80% of full ROM. Phase 2 guides a smooth transition to full weightbearing, so the patient may regain functional independence. Phase 3 helps the patient become recreationally asymptomatic and restores muscular strength and endurance. Finally, phase 4 culminates in the pain-free return to competitive sports or recreational activity. At this time, there exists no single, unanimously agreed upon postoperative physical therapy protocol. Among the current recommendations, variation exists regarding specific timelines, restrictions, precautions, exercises, and techniques throughout the four phases. It is imperative to reduce ambiguity in current recommendations and more specifically define postoperative physical therapy following operative management of FAIS to more expeditiously return patients to functional independence and physical activity.

Gadolinium injected concurrently with anesthetic can result in false-negative diagnostic intra-articular hip injections.

PURPOSE: The purpose of this paper was to evaluate the response to intra-articular hip injections with and without concurrent gadolinium administration. Our secondary outcome was to compare post-operative outcomes between patients with an initial false-negative gadolinium-containing injection and a matched control group. METHODS: Patients receiving a series of two hip diagnostic intra-articular injections (DIAI), the first with gadolinium for concurrent MRA and the second without gadolinium, were retrospectively identified. Pain response to DIAI, injectate volume, local anesthetic volume, inclusion of corticosteroids, and method of injection were compared between injections. False-negative injection was defined as < 50% pain relief with concurrent gadolinium, but ≥ 50% pain relief with subsequent anesthetic injection without gadolinium. False-negative injections in patients that ultimately underwent primary hip arthroscopy were identified from this cohort and matched in a 3:1 ratio to a control cohort to compare short-term post-operative single assessment numerical evaluation (SANE) outcomes. RESULTS: Forty-three patients underwent a series of anesthetic injections with and without gadolinium and met inclusion and exclusion criteria. Pain response was significantly different in injections performed with and without gadolinium (18% vs. 81%; p < 0.001). There were significant differences in total injectate volume, local anesthetic volume, corticosteroid use, and method of injection between injections, but these variables were not correlated with pain response. Fifteen patients with false-negative responses to injection underwent primary hip arthroscopy and were matched in a 3:1 ratio to a control cohort. There was no difference in short-term post-operative SANE scores between the gadolinium-sensitive and control groups (81.6 vs. 80.0, n.s.). CONCLUSION: Concurrent administration of intra-articular gadolinium with DIAI may result in a false-negative response to anesthetic. Additionally, in patients with initial false-negative DIAI with gadolinium, short-term post-operative outcomes after hip arthroscopy are similar to a matched cohort. LEVEL OF EVIDENCE: Level III.

Reliability of Conventional Hip MRI in Detecting Labral Tear and Labrocartilagenous Lesions in cases of Femoroacetabular Impingement, A Comparative Study with Hip Arthroscopy.

BACKGROUND: Imaging studies play a crucial role in diagnosing femoroacetabular impingement (FAI), including plain radiography and Magnetic Resonance Imaging (MRI). FAI is a combined pathology of bony abnormality, labral and labrocartilagenous erosions. Surgical treatment for such cases has become more established and preoperative imaging is the roadmap that includes the assessment of labrum and articular cartilage. METHODS: During a period of 2 years, thirty-seven patients with a clinical diagnosis of FAI were retrospectively enrolled in this study, including 17 men and 20 women, aged 27-62 years. There were 22 right hips and 15 left hips. MRI was done for all patients to identify bony details, labral and chondral abnormalities and to exclude coexisting disorders. The imaging findings were compared with the arthroscopic data. RESULTS: 15 patients had Pincer FAI, 11 patients had CAM, and 11 patients had combined Cam/Pincer FAI. Labral tear was detected in 100 % of patients, 97 % had an anterosuperior labral tear. 82 % of patients had partial thickness cartilage lesions and 8 % had full thickness cartilage lesions. MRI had a sensitivity of 100 % compared to hip arthroscopy in detecting labral tear, 60 % in detecting cartilage erosion. CONCLUSION: Conventional hip MRI detects bony changes in FAI, type of impingement and associated labral tear and cartilage erosions in comparison to the hip arthroscopy.

The Female Pelvis Is Associated with a Lateralized Ischium and a Reduced Ischiofemoral Space.

BACKGROUND: Pelvi-femoral conflicts are increasingly recognized for their explanatory role in the pathology of extra-articular hip impingement. Ischiofemoral impingement (IFI) is a type of impingement between the femur and the ischium that causes high femoral antetorsion and valgus femoral neck orientation. It is unknown whether obstetric adaptation of the female pelvis renders the female hip at a higher risk of sustaining IFI. The aim of this study was to determine the influence of the pelvic morphology on the ischiofemoral space (IFS). METHODS: Plain radiographs of healthy individuals with no symptomatic hip disease were obtained in a functional standing position in a standardized manner and utilized for measurement of the interischial and ischiofemoral widths, subpubic angle, and centrum collum diaphyseal (CCD) angle. Linear regression was performed to determine the influence of morphometric measures on the ischiofemoral space. RESULTS: Sixty-five radiographs (34 females and 31 males) were included. The cohort was stratified according to gender. Significant gender-related differences were noted regarding the ischiofemoral distance (31% increase in males, p < 0.001), pubic-arc angle (30% increased in females, p < 0.001), and the interischial space (7% increase in females, p < 0.001). CCD did not significantly differ between genders (p = 0.2). Factors influencing the IFS include the pubic-arc angle (ß = -0.01 (CI -0.02--0.00), p = 0.003), interischial distance (ß = -0.11 (CI -0.23--0.00), p = 0.049) and CCD (ß = -0.06 (CI -0.09--0.04), p < 0.001). CONCLUSIONS: Obstetric adaptation is associated with an increased subpubic angle that shifts the ischia laterally and away from the symphysis. The resultant reduction in the ischiofemoral space renders the female pelvis at a higher risk for a pelvi-femoral conflict, or more precisely, an ischiofemoral conflict, due to the reduced ischiofemoral space of the hip. The CCD angle of the femur was shown not to be gender specific. However, the CCD angle demonstrates an influence on the ischiofemoral space, rendering the proximal femur a target for corresponding osteotomies.

Femoral impingement in maximal hip flexion is anterior-inferior distal to the cam deformity in femoroacetabular impingement patients with femoral retroversion : implications for hip arthroscopy.

AIMS: Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients. METHODS: A retrospective study involving 24 patients (37 hips) with FAI and femoral retroversion (femoral version (FV) < 5° per Murphy method) was performed. All patients were symptomatic (mean age 28 years (SD 9)) and had anterior hip/groin pain and a positive anterior impingement test. Cam- and pincer-type subgroups were analyzed. Patients were compared to an asymptomatic control group (26 hips). All patients underwent pelvic CT scans to generate personalized CT-based 3D models and validated software for patient-specific impingement simulation (equidistant method). RESULTS: Mean impingement-free flexion of patients with mixed-type FAI (110° (SD 8°)) and patients with pincer-type FAI (112° (SD 8°)) was significantly (p < 0.001) lower compared to the control group (125° (SD 13°)). The frequency of extra-articular subspine impingement was significantly (p < 0.001) increased in patients with pincer-type FAI (57%) compared to cam-type FAI (22%) in 125° flexion. Bony impingement in maximal flexion was located anterior-inferior at femoral four and five o'clock position in patients with cam-type FAI (63% (10 of 16 hips) and 37% (6 of 10 hips)), and did not involve the cam deformity. The cam deformity did not cause impingement in maximal flexion. CONCLUSION: Femoral impingement in maximal flexion was located anterior-inferior distal to the cam deformity. This differs to previous studies, a finding which could be important for FAI patients in order to avoid exacerbation of hip pain in deep flexion (e.g. during squats) and for hip arthroscopy (hip-preservation surgery) for planning of bone resection. Hip impingement in flexion has implications for daily activities (e.g. putting on shoes), sports, and sex.Cite this article: Bone Joint Res 2023;12(1):22-32.

Characterization of pincer-type Hip impingement in professional women's ice hockey players.

OBJECTIVE: Femoroacetabular impingement (FAI) appears common in ice hockey, but there is a lack of data examining pincer-type impingement in women's ice hockey athletes. The objective of this study was to assess the prevalence of pincer-type impingement in National Women's Hockey League (NWHL) athletes. Our hypothesis was that there would be an increased prevalence of pincer impingement in these athletes. METHODS: Data were gathered for a team of NWHL players, and age, gender, and body mass index (BMI) matched controls were also retrospectively collected. All subjects were above 18 years of age. Control patients were excluded if they had undergone prior hip surgery, were greater than age 30, or had BMI greater than 35. Radiographs of both groups were assessed for lateral center edge angle (LCEA), Tönnis angle, and crossover sign. Tönnis angle <0 or LCEA >40 degrees was considered pincer morphology. An alpha angle >55 degrees was considered cam morphology. RESULTS: Thirty-seven NWHL players and 37 female controls were included. Overall 32% of the players had a pincer lesion in either hip based on LCEA, 8% had a Tönnis angle <0, and 22% had a crossover sign in either hip compared to 9%, 19%, and 13% for the controls, respectively. None of these findings were significantly different between the groups (p > 0.05). An alpha angle ≥55 degrees in either hip was found in 84% of players, but lateral Dunn images for alpha angle measurements were not available for the control group. CONCLUSIONS: Pincer-type morphology and crossover signs were present in a larger portion of NWHL players than has been reported in the general population, but these findings were not statistically different than in the control group. Cam-type morphology was even more prevalent in these athletes and may be related to age at menarche due impingement at the physis prior to closure.

Intra-articular Hip Injuries in National Basketball Association Players: A Descriptive Epidemiological Study.

Background: Since the most recent epidemiologic study of injuries in National Basketball Association (NBA) players was completed in 2012, the understanding and diagnosis of intra-articular hip injury has advanced. Purpose: To report the epidemiology of intra- versus extra-articular hip injuries in NBA players with regard to missed games, risk factors for injury, and treatment types. Study Design: Cohort study; Level of evidence, 3. Methods: The NBA injury database was queried for all reported hip and groin injuries from 2013 to 2017. The injuries were then divided into intra-articular and extra-articular types. Variables compared between injury types included player age, NBA tenure, season schedule (preseason or offseason), onset type, injury mechanism, roster position, games missed, time to return to play, and need for surgery. Results: A total of 224 athletes sustaining 353 total hip pathologies were identified. Of these injuries, 216 (61.2%) were sustained during game competition and affected 156 (69.6%) of the athletes. Intra-articular injuries represented 39 (11.0%) cases and involved 36 (16.1%) players. The time to return to play was significantly longer after intra-articular versus extra-articular injury (44.6 ± 96.0 vs 11.8 ± 32.0 days; P = .03), and the number of games missed was significantly greater after intra-articular versus extra-articular injury (8.0 ± 18.7 vs 1.54 ± 4.9 games; P = .03). Patients with intra-articular hip injuries were more likely to undergo surgery (odds ratio, 5.5 [95% CI, 1.8-16.7]; P = .005). There was no statistically significant difference in the number of games missed due to surgery (35.2 ± 8.3 [intra-articular] vs 35.4 ± 11.6 [extra-articular]; P = .42) or nonoperative treatment (4.2 ± 3.4 [intra-articular] vs 1.3 ± 0.5 [extra-articular]; P = .11). Years of NBA tenure were not significantly different between intra-articular and extra-articular injuries (7.1 ± 3.7 vs 6.3 ± 4.0 years). For both types of hip injury, there was no correlation between player age and either days to return to play or number of games missed (R 2 = 0.014). Conclusion: NBA players with intra-articular hip injuries underwent surgery more frequently and had a longer return-to-play time compared with those with extra-articular hip injuries. NBA tenure and player age were not correlated with the risk of developing hip injury or the need for surgery.

Hip Impingement Location in Maximal Hip Flexion in Patients With Femoroacetabular Impingement With and Without Femoral Retroversion.

BACKGROUND: Symptomatic patients with femoroacetabular impingement (FAI) have limitations in daily activities and sports and report the exacerbation of hip pain in deep flexion. Yet, the exact impingement location in deep flexion and the effect of femoral version (FV) are unclear. PURPOSE: To investigate the acetabular and femoral locations of intra- or extra-articular hip impingement in flexion in patients with FAI with and without femoral retroversion. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: An institutional review board-approved retrospective study involving 84 hips (68 participants) was performed. Of these, symptomatic patients (37 hips) with anterior FAI and femoral retroversion (FV <5°) were compared with symptomatic patients (21 hips) with anterior FAI (normal FV) and with a control group (26 asymptomatic hips without FAI and normal FV). All patients were symptomatic, had anterior hip pain, and had positive anterior impingement test findings. Most of the patients had hip/groin pain in maximal flexion or deep flexion or during sports. All 84 hips underwent pelvic computed tomography (CT) to measure FV as well as validated dynamic impingement simulation with patient-specific CT-based 3-dimensional models using the equidistant method. RESULTS: In maximal hip flexion, femoral impingement was located anterior-inferior at 4 o'clock (57%) and 5 o'clock (32%) in patients with femoral retroversion and mostly at 5 o'clock in patients without femoral retroversion (69%) and in asymptomatic controls (76%). Acetabular intra-articular impingement was located anterior-superior (2 o'clock) in all 3 groups. In 125° of flexion, patients with femoral retroversion had a significantly (P < .001) higher prevalence of anterior extra-articular subspine impingement (54%) and anterior intra-articular impingement (89%) compared with the control group (29% and 62%, respectively). CONCLUSION: Knowing the exact location of hip impingement in deep flexion has implications for surgical treatment, sports, and physical therapy and confirms previous recommendations: Deep flexion (eg, during squats/lunges) should be avoided in patients with FAI and even more in patients with femoral retroversion. Patients with femoral retroversion may benefit and have less pain when avoiding deep flexion. For these patients, the femoral location of the impingement conflict in flexion was different (anterior-inferior) and distal to the cam deformity compared with the location during the anterior impingement test (anterior-superior). This could be important for preoperative planning and bone resection (cam resection or acetabular rim trimming) during hip arthroscopy or open hip preservation surgery to ensure that the region of impingement is appropriately identified before treatment.

Effect of Osteochondroplasty on Time to Reoperation After Arthroscopic Management of Femoroacetabular Impingement: Analysis of a Randomized Controlled Trial.

Background: A subset of patients with femoroacetabular impingement (FAI) fail arthroscopic management. It is not clear which patients will fail surgical management; however, several surgical and patient factors, such as type of procedure and age, are thought to be important predictors. Purpose: This time-to-event analysis with a 27-month follow-up analysis compared the effect of (1) arthroscopic osteochondroplasty with or without labral repair versus (2) arthroscopic lavage with or without labral repair on the time to reoperation in adults aged 18 to 50 years with FAI. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Eligible participants had been randomized in a previous study trial to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage with or without labral repair. Using the comprehensive data set from the Multinational Femoroacetabular Impingement Randomized controlled Trial, all reoperations until 27 months after surgery were identified. The analysis was conducted using a Cox proportional hazards model, with percentage of patients with a reoperation evaluated in a time-to-event analysis as the outcome. The independent variable was the procedure, with age and impingement subtype explored as potential covariates. The effects from the Cox model were expressed as the hazard ratio (HR). All tests were 2-sided, with an alpha level of .05. Results: A total of 108 patients in the osteochondroplasty group and 106 patients in the lavage group were included. The mean age of the patients included in the study was 36 ± 8.5 years. Overall, 27 incident reoperations were identified within the 27-month follow-up, with an incidence rate of 6 per 100 person-years. Within the osteochondroplasty group, 8 incident reoperations were identified (incidence rate, 3.4 per 100 person-years), while within the lavage group, 19 incident reoperations were identified (incidence rate, 8.7 per 100 person-years). The hazard of reoperation for patients undergoing osteochondroplasty was 40% of that of patients undergoing lavage (HR, 0.40 [95% CI, 0.17-0.91] P = .029). Conclusion: This study demonstrated that for adults between the ages of 18 and 50 years with FAI, arthroscopic osteochondroplasty was associated with a 2.5-fold decrease in the hazard of reoperation at any point in time compared with arthroscopic lavage. Registration: NCT01623843 (ClinicalTrials.gov identifier).

Iliocapsularis: An exploration of the muscle and its omission in education.

Anterior hip joint musculature is classically characterized to include iliacus, psoas major, rectus femoris, and sartorius muscles. A lesser-known muscle, iliocapsularis muscle (ICm), has made infrequent appearances in the literature for the last ~70 years, but potentially has important functional and clinical value. The purpose of this study is to review the historical prevalence of the ICm in peer-reviewed literature (PRL), further explore the prevalence of the muscle in current anatomical textbooks (ATBs), characterize the muscle with a new series of dissections, assess the muscle's perceived importance to clinicians and educators, and comment on the possible functional significance of the muscle. The ICm was mentioned in 28 peer-reviewed articles and the muscle was present in 518 of 521 (99%) dissected hips in 13 publications which assessed prevalence. In an audit of 30 recently published ATBs, three texts mentioned the ICm. In 28 anterior hip dissections performed in the current study, the muscle was present in all hips. Anatomy educators were surveyed to determine if the ICm was presently taught in their curricula, and clinicians of various specialties were surveyed regarding their perceptions of the ICm and its clinical relevance. The ICm inclusivity within anatomical curricula from educators reported 8.5%, while 4% of clinicians reported trainees should have an educational background of the ICm. This study confirms that while the ICm is present within PRL, and is ubiquitous amongst human-donor dissection, the ICm is not mentioned in most ATBs and is absent in the vast majority of anatomical curricula. Lack of inclusion in curricula may lead to a perceived insignificance to currently practicing clinicians despite the potential functional importance at the hip. This discordance suggests that the ICm should be included in ATBs and anatomical curricula so that future clinicians can consider the ICm when evaluating and treating patients.

Most of patients with femoral derotation osteotomy for posterior extraarticular hip impingement and high femoral version would do surgery again.

AIMS: To assess (1) hip pain and function and ROM; (2) subsequent surgeries, complications; and (3) subjective satisfaction and PROMs in patients undergoing femoral derotation osteotomies. METHODS: Femoral derotation subtrochanteric osteotomies to treat symptomatic posterior extraarticular ischiofemoral hip impingement were performed in 23 patients (25 hips) between 2013 and 2017. The mean age was 26 ± 8 years (96% female) with a minimum 2-year follow-up (mean follow-up of 4 ± 1 years). Surgical indication was a positive posterior impingement test and limited external rotation (mean 16° ± 8°) in extension in patients with abnormal high femoral version (mean 46° ± 9, measured on CT scans with the Murphy method) and high McKibbin instability index (mean 67°). Femoral osteotomies were combined with a surgical hip dislocation in 96% for cam resection and labrum or cartilage treatment. Preoperative MRI and 3D-CT with dynamic impingement simulation were evaluated. RESULTS: (1) The posterior impingement test decreased significantly from preoperatively 100% to 4% (p < 0.001). External rotation in extension increased significantly (p < 0.001) from preoperative 16° ± 8 to 44° ± 16°. The MdA score increased significantly from 14 ± 1 to 16 ± 2 (p < 0.001) points.(2) At follow-up, all 25 hips were preserved. No conversion to THA and no revision osteosynthesis was performed. 64% underwent complete hardware removal.(3) 80% of the patients reported at follow-up that they would undergo surgery again. Subjective satisfaction (SHV) increased significantly (p < 0.001) from preoperatively 24% to 84% postoperatively. CONCLUSIONS: Femoral derotation subtrochanteric osteotomies for the treatment of posterior extraarticular ischiofemoral hip impingement are safe and improve posterior hip pain and function and external rotation in mostly female patients with high femoral version and a high McKibbin instability index.

Rotation osteotomy of the distal femur influences coronal femoral alignment and the ischiofemoral space.

INTRODUCTION: Despite the fact that osteotomies around the knee represent well-established treatment options for the redistribution of loads and forces within and around the knee joint, unforeseen effects of these osteotomies on the remaining planes and adjacent joints are still to be defined. It was, therefore, the aim of this study to determine the influence of a distal femoral rotation osteotomy on the coronal limb alignment and on the ischiofemoral space of the hip joint. MATERIALS AND METHODS: Long-leg standing radiographs and CT-based torsional measurements of 27 patients undergoing supracondylar rotational osteotomies of the femur between 2012 and 2019 were obtained and utilized for the purpose of this study. Postoperative radiographs were obtained after union at the osteotomy site. The hip-knee-ankle angle (HKA), the mechanical lateral distal femur angle (mLDFA), and the ischiofemoral space were measured. Comparison between means was performed using the Wilcoxon-Mann-Whitney test. RESULTS: Twenty-seven patients underwent isolated supracondylar external rotation osteotomy to reduce the overall antetorsion of the femur. The osteotomy resulted in a 2.4° ± 1.4° mean increase in HKA and 2.4 mm ± 1.7 mm increase in the ischiofemoral space (p < 0.001). CONCLUSION: Supracondylar external rotation osteotomy of the femur leads to valgisation of the coronal limb alignment and increases the ischiofemoral space. This is resultant to the reorientation of the femoral antecurvature and the femoral neck. When planning a rotational osteotomy of the lower limb, this should be appreciated and may also aid in the decision regarding osteotomy site.