The technical advances in arthroscopic surgery of the hip, including the improved ability to manage the capsule and gain extensile exposure, have been paralleled by a growth in the number of conditions that can be addressed. This expanding list includes symptomatic labral tears, chondral lesions, injuries of the ligamentum teres, femoroacetabular impingement (FAI), capsular laxity and instability, and various extra-articular disorders, including snapping hip syndromes. With a careful diagnostic evaluation and technical execution of well-indicated procedures, arthroscopic surgery of the hip can achieve successful clinical outcomes, with predictable improvements in function and pre-injury levels of physical activity for many patients.

This paper reviews the current position in relation to the use of arthroscopy in the treatment of disorders of the hip.

Cite this article: Bone Joint J 2013;95-B:10–19.

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells. Cite this article: Bone Joint Res 2020;9(12):857–869

Purpose. Factors contributing to chronic postoperative pain (CPOP) are poorly defined in young people and developmental considerations are poorly understood. With over 5 million children undergoing surgery yearly and 25% of adults referred to chronic pain clinics identifying surgery as the antecedent, there is a need to elucidate factors that contribute to CPOP in young people. The present study includes patients undergoing hip preservation surgery at a children's hospital. Methods. The HOOS and the SF-12 Health Survey were administered to 614 patients prior to surgery with 422 patients completing follow-up data (6-months, 1-year, and 2-years post-surgery). Examining baseline characteristics for those who completed follow-up versus those who did not, the only significant difference was that patients with more than one surgery were less likely to complete follow-up measures. Pain, quality of life, and functioning across time were examined using SAS PROC TRAJ procedure, a mixture model that estimates a regression model for each discrete group within the population. Longitudinal pain trajectories were empirically grouped. Baseline preoperative characteristics of age, gender, preoperative pain, quality of life, functioning, and mental health that could potentially distinguish trajectory groups were examined. Results. A three trajectory model (low pain, pain improvement, and high pain) emerged indicating three different treatment responders. Pain trajectory groups did not differ significantly on gender, presurgical age, BMI, prior hip surgery, surgical type, joint congruence, or Tönnis grade. The pain trajectory groups differed significantly from each other on presurgical pain, pain chronicity, quality of life, and functioning. Those in the high pain group and pain improvement group endorsed having presurgical depression at significantly higher rates and lower presurgical quality of life compared to those in the low pain group (p<.01). Similarly, those in the high pain group reported significantly worse functioning prior to surgery compared to the pain improvement group (p<.0001) and those in the low pain group (p<.0001). Conclusions. Chronic pain is a common problem and surgery can be a trigger. There may be a subset of hip preservation surgery patients who are predisposed to chronic pain independent of hip health. The results demonstrate the need for preoperative screening prior to hip preservation surgery. A prospective, interventional study to identify patients at risk for a poor pain trajectory is underway. Significance. This is the largest study to date to examine longitudinal pain, quality of life, and functioning trajectories for adolescent and young adults undergoing hip preservation surgery. Chronic pain is a serious public health concern, with the United States spending $19 billion annually on pain-related disability. Identifying predictors of poor long-term outcomes in adolescents and young adult samples with postoperative pain may prevent the development of chronic pain into adulthood as well as inform presurgical preparation and postsurgical care

Management of the young adult hip pathologies is a special entity in orthopaedic surgical practice that needs special emphasis and consideration. A wide range of pathological and traumatic conditions occur in the young adult hip that lead to functional disability and the development of premature osteoarthritis. Proper surgical interference when the hip is still in the pre-arthritic stage restores function to the young hip and protects it from early degenerative changes, and hence the anticipated need for future joint replacement surgery is prevented. Accurate estimation of the biomechanical error combined with careful understanding of the hip joint biology is the cornerstone of success of any hip preservation surgery ever performed to save the young adult hip. Safe surgical hip dislocation approach was adopted as one of the tools in the hands of the hip preservation surgeon to treat a broad spectrum of intra-articular hip pathologies like Perthes disease and severe forms of slipped capital femoral epiphysis (SCFE). Osteo-chondroplasty at the head-neck junction with relative femoral neck lengthening for Perthes disease, and Subcapital re-orientation of severe SCFE based on its retinacular vascular pedicle are often performed via the surgical hip dislocation approach. The approach is also useful with certain types of acetabular fractures that enables fixation of dual-column fractures via single approach with intra-articular visualization for the accuracy of reduction and hardware placement. The 4 cm mini-open direct anterior approach is ideal for the surgical treatment of cases with cam and/or pincer types of femoro-acetabular impingement. Peri-articular osteotomies performed either on the acetabular or the femoral sides of the hip joint are extremely useful in the correction of the biomechanical error that led to an existing hip pathology. Periacetabular osteotomies are commonly performed to treat dysplasia of the young hip. Proximal femoral osteotomies are commonly performed to treat a wide range of hip pathologies including non-unions of femoral neck fractures in the young adult. Correction of the biomechanical error at the proper timing ensures normalization of the hip joint loading conditions and range of motion that leads to reversal of the pathologic process and prevention of osteoarthritis. A hip joint replacement would have an unknown but certainly a finite life, whereas a young hip that has healed after hip preservation surgery would definitely last for a lifetime

Background. This study aimed to investigate the effect of body mass index (BMI) on functional outcome following hip preservation surgery using the U.K. Non-Arthroplasty Hip Registry (NAHR). Methods. Data on adult patients who underwent hip arthroscopy or periacetabular osteotomy (PAO) between January 2012 and December 2018 was extracted from the UK Non-Arthroplasty Hip Registry dataset allowing a minimum of 12 months follow-up. Data is collected via an online clinician and patient portal. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months. Results. A total of 6,666 patients were identified with BMI data available in 52%, comprising 3,220 arthroscopies and 277 PAO. Patients were divided into WHO groups: <25kg/m. 2. (n=1,745 (49.8%)), 25–30kg/m. 2. (n=1,199 (34.2%)), and ≥30kg/m. 2. (n=562 (16.0%)). Patients with higher BMI tended to be older. Pre-operative, 6 and 12-month follow-up were available for 91%, 49% and 45% of cases respectively. Higher BMI was associated with significantly poorer baseline, 6- and 12-month outcomes (12-month mean iHOT-12 score: <25kg/m. 2. = 62.3 (95%CI 60.4 to 64.3), 25–30kg/m. 2. = 57.3 (95%CI 55.0 to 59.7), ≥30kg/m. 2. = 54.7 (95%CI 51.1 to 58.2)). However, all groups saw similar and statistically significant improvement in pre- vs post-op scores (mean 12-month iHOT-12 gain: <25kg/m. 2. = +27.1 (95%CI 25.1 to 29.0), 25–30kg/m. 2. = +26.5 (95%CI 24.0 to 29.0), ≥30kg/m. 2. = +26.8 (95%CI 23.2 to 30.4), between-group p = 0.9). EQ-5D outcomes followed the same trend. Modelling for age, sex and procedure we found no significant difference in 12-month iHOT-12 gain between BMI groups. Conclusion. Whilst obese patients started from, and achieved lower post-operative raw functional scores, all BMI groups saw similar and significant degrees of improvement in functional outcome post-operatively. Obesity should not be considered a contraindication to hip preservation surgery

This study aims to describe the characteristics and outcomes of patients who reported their pre-operative quality of life (QoL) was ‘worse than death’ (‘WTD’) prior to hip arthroscopy (HA) or peri-acetabular osteotomy (PAO). Adult patients who underwent HA or PAO between 1. st. January 2012 and 31. st. October 2020 were extracted from the UK Non-Arthroplasty Hip Registry. International Hip Outcome Tool 12 (iHOT-12) and EuroQol-5 Dimensions (EQ-5D) index questionnaires were collected pre-operatively and at 6 and 12 months. WTD was defined as an EQ-5D score of less than zero. Chi-squared and t-tests were used to compare categorical and continuous variables respectively. 8493 procedures (6355 HA, 746 PAO) were identified in whom 7101 (84%) returned pre-operative EQ-5D questionnaires. 283 HA and 52 PAOs declared their pre-operative QoL to be ‘WTD’. Compared to those patients with pre-operative QoL ‘better than death’ (n=6072, control group) (EQ-5D ≥ zero) patients reporting ‘WTD’ function prior to HA were more likely to be female (66% vs 59%, p = 0.013), of higher body mass index (mean 27.6 kg/m. 2. (SD 5.9) vs 25.7 kg/m. 2. (4.5), p < 0.0001) however there were no statistically significant differences in mean age (36.8 vs 36.4 years), femoroacetabular impingement pattern, or femoral or acetabular cartilage lesion severity. There were no significant demographic differences for PAO. For HA, iHOT-12 scores in WTD patients were significantly poorer pre- [10.8 (95% CI 9.6 to 12.0) vs 33.3 (32.8 to 33.8)] and 12 months post-operatively [34.9 (29.0 to 40.8) vs 59.3 (58.2 to 60.4)] compared to controls. Whilst the majority of patients saw improvement in their scores (p <0.0001), a significantly smaller proportion achieved the minimum clinically important difference for iHOT-12 by 12 months. (51% in the WTD group vs 65% in the control group). Similar trends were observed for PAO. Patients with WTD quality of life may benefit less from hip preservation surgery and should be counselled accordingly regarding expectations. Although the scores improve, only 51% achieve scores beyond MCID

Aims. Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head. Methods. In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8). Results. Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032). Conclusion. At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression. Cite this article: Bone Jt Open 2021;2(11):926–931

There are three major diagnoses that have been associated with early hip degeneration and subsequent hip replacement in young patients: FAI, hip dysplasia and hip osteonecrosis. I will focus mainly on the first two. Both conditions, if diagnosed early in the symptomatic patient, can be surgically treated in order to try to prevent further hip degeneration. But, what is the natural history of these disorders?

Our recent paper published this year described the natural history of hip dysplasia in a group of patients with a contralateral THA. At an average of 20 years, 70% of hips that were diagnosed at Tönnis Grade 0, had progression in degenerative changes with 23% requiring a THA at 20 years. Once the hip degeneration progressed to Tönnis 1, then 60% of hips progressed and required a THA. This natural history study demonstrates that degeneration of a dysplastic hip will occur in over 2/3 of the hips despite the limitations of activity imposed by a contralateral THA.

In this same study, we were unable to detect a significant difference in progression between FAI hips and those categorised as normal. FAI damage has been commonly considered to be “motion-induced” and as such, the limitations imposed by the THA, might have limited the progression in hip damage. Needless to say, progression was seen in about half of the hips at 10 years, but very few required a THA at final follow-up. We have recently presented data on a group of young asymptomatic teenagers with FAI. At 5 years of follow-up, the group of patients with limited ROM in flexion and internal rotation, cam deformity and increased alpha angles, depicting a more severe form of disease, showed MRI evidence of progression in hip damage and worst clinical scores than a control group. This data supports our initial impressions that FAI may truly lead to irreversible hip damage.

Is surgery always the option? I indicate surgery when the patient is symptomatic and has a correctable structural problem that has failed non-operative management. The data suggests that few patients improve with physical therapy, but activity modification may be an option in patients with FAI as the hip damage is mainly activity related. This may not be the case with hip dysplasia. For hip dysplasia, my current recommendations are in the form of a periacetabular osteotomy (PAO) to correct the structural problem. The procedure leads to improvement in pain as it takes care of the 4 pain generators in the dysplastic hip: the labrum, cartilage, abductors, and resultant instability. The labrum and cartilage are off-loaded with the PAO, the instability is improved by providing containment and the abductor pain is improved by improving the hip mechanics by medializing the acetabulum. I perform a hip arthroscopy prior to the PAO in the majority to treat the labrum and to perform a head neck junction osteochondroplasty, if needed. Correction of the dysplasia to a more normal hip, will improve the outcome of these hips in the long-term.

For FAI, arthroscopy has become the best option for management and today is considered the gold standard. A careful review of the imaging is important prior to surgical decision making as patient selection and surgical correction is key. Poor outcomes have been seen in patients with advanced degenerative changes (joint space narrowing, femoral head damage) or in patients with incomplete correction of the deformity. Open surgical correction is an option in cases where deformity precludes an arthroscopic treatment alone.

Over the past fifteen years hip preservation surgery has rapidly evolved. Improved understanding of the pathomechanics and associated intra-articular degeneration of both hip instability and femoroacetabular impingement have led to improved surgical indications, refined surgical techniques and more effective joint preservation surgical procedures. The periacetabular osteotomy (PAO) was initially introduced by Ganz and colleagues and has become the preferred treatment in North America for pre-arthritic, symptomatic acetabular dysplasia. Both hip arthroscopy and safe surgical dislocation of the hip have been popularised for the treatment of symptomatic femoroacetabular impingement disorders. Hip arthroscopy is effective for focal and\or accessible impingement lesions while the surgical dislocation approach is reserved for nonfocal disease patterns as seen in complex FAI, and residual Perthes and SCFE deformities. Femoroacetabular impingement from major acetabular retroversion can be managed with the PAO if there is coexistent posterosuperior acetabular insufficiency. Short- to mid-term results of these procedures are generally good to excellent for most patients and the complication rates associated with these procedures are very acceptable. Long-term outcomes are best known for the PAO. Several recent studies have documented survivorship rates of 65–90% at 10–20-year follow-up. Certain factors are associated with long-term success including minimal pre-operative radiographic OA, early symptoms, accurate acetabular correction, and younger age. These data strongly suggest that the PAO can defer THA to an older age for most patients while completely avoiding arthroplasty may only be possible in select patients with excellent congruency, no secondary OA and an ideal surgical correction

Aims

The lateral centre-edge angle (LCEA) is a plain radiological measure of superolateral cover of the femoral head. This study aims to establish the correlation between 2D radiological and 3D CT measurements of acetabular morphology, and to describe the relationship between LCEA and femoral head cover (FHC).

Hip joint preservation remains a preferred treatment option for hips with mechanically correctable pathologies prior to the development of significant secondary arthrosis. The pathologies most amenable to joint preservation are hip dysplasia and femoroacetabular impingement. These pathologies sometimes overlap. Untreated acetabular dysplasia of modest severity always leads to arthrosis if uncorrected. Acetabular dysplasia is best treated by periacetabular osteotomy, usually combined with arthrotomy for management of labral pathology and associated cam-impingement if present. Pre-operative variables associated with the best long-term outcomes include less secondary arthrosis, younger age, and concentric articular surfaces. The earlier PAO series show 20 year survivorship of 81% and 65% in Tonnis Grade 0 and 1 hips. Femoroacetabular impingement has become progressively recognised as perhaps the most common cause of secondary arthrosis. The etiology of impingement is multifactorial and includes both genetic factors and stresses experienced by the hip prior to cessation of growth. Cam impingement can be quantified by the alpha angle as measured on plain radiographs and radial MR sequences. Cam impingement can be treated by arthroscopic or open femoral head-neck osteochondroplasty. As with hip dysplasia, prognosis following treatment is correlated with the severity of pre-operative secondary arthrosis but unfortunately impinging hips more commonly have some degree of arthrosis pre-operatively whereas dysplastic hips can become symptomatic with instability in the absence of arthrosis. The scientific basis for the treatment of pincer impingement is less strong. Unlike cam impingement and hip dysplasia, pincer impingement pathology in the absence of coxa profunda has not been correlated with arthrosis and so rim trimming with labral refixation is probably performed more often than is clinically indicated. Overall, joint preserving surgery remains the preferred treatment for hips with mechanically correctable problems prior to the development of significant secondary arthrosis

Hip joint preservation remains a preferred treatment option for hips with mechanically correctable pathologies prior to the development of significant secondary arthrosis. The pathologies most amenable to joint preservation are hip dysplasia and femoroacetabular impingement. These pathologies sometimes overlap. Untreated acetabular dysplasia of modest severity always leads to arthrosis if uncorrected. Acetabular dysplasia is best treated by periacetabular osteotomy, usually combined with arthrotomy for management of labral pathology and associated cam-impingement if present. Preoperative variables associated with the best long-term outcomes include less secondary arthrosis, younger age, and concentric articular surfaces. Femoroacetabular impingement has become progressively recognised as perhaps the most common cause of secondary arthrosis. The etiology of impingement is multifactorial and includes both genetic factors and stresses experienced by the hip prior to cessation of growth. Cam impingement can be quantified by the alpha angle as measured on plain radiographs and radial MR sequences. Cam impingement can be treated by arthroscopic or open femoral head-neck osteochondroplasty. As with hip dysplasia, prognosis following treatment is correlated with the severity of preoperative secondary arthrosis but unfortunately impinging hips more commonly have some degree of arthrosis preop whereas dysplastic hips can become symptomic with instability in the absence of arthrosis. The scientific basis for the treatment of pincer impingement is less strong. Unlike cam impingement and hip dysplasia, pincer impingement pathology in the absence of coxa profunda has not been correlated with arthrosis and so rim trimming with labral refixation is probably performed more often than is clinically indicated. Overall, joint preserving surgery remains the preferred treatment for hips with mechanically correctible problems prior to the development of significant secondary arthrosis

There are a number of progressive conditions that afflict the hip and result in degenerative arthritis. Along the path of progression of the disease and prior to the development of arthritis, some of these conditions may be treatable by joint preservation procedures. Periacetabular osteotomy for developmental dysplasia of the hip (DDH), femoroacetabular osteoplasty for femoroacetabular impingement (FAI), and a variety of surgical procedures for management of early osteonecrosis of the femoral head are some examples of joint preservation of the hip. DDH is characterised by abnormal development of the acetabulum and the proximal femur that leads to suboptimal contact of the articular surfaces and the resultant increase in joint reaction forces. FAI is a condition characterised by an abnormal contact between the femoral neck and the acetabular rim. FAI is believed to exist when a triad of signs (abnormal alpha angle, labral tear, and chondral lesion) can be identified.

The question that remains is whether joint preservation procedures are able to avert the need for arthroplasty or just an intervention along the natural path of progression of the hip disease. There is an interesting study that followed 628 infants born in a Navajo reservation, including 8 infants with severe dysplasia, for 35 years. None of the children with DDH had surgical treatment and all had developed severe arthritis in the interim. The latter study and a few other natural history studies have shown that the lack of administration of surgical treatment to patients with symptomatic DDH results in accelerated arthritis. The situation is not so clear with FAI. Some believe that FAI is a pre-arthritic condition and surgical treatment is only effective in addressing the symptoms and does not delay or defer an arthroplasty. While others believe that restoration of the normal mechanical environment to the hip of FAI patients, by removing the abnormal contact and repair of the labrum, is likely to change the natural history of the disease and at minimum delay the need for an arthroplasty. There is a need for natural history studies or case series to settle the latter controversy.

Surgical invention to preserve the native hip joint remains a preferred treatment option for hips in young patients with mechanically correctable pathologies prior to the development of significant secondary arthrosis. The two most common pathologies most amenable to joint preservation are hip dysplasia and femoroacetabular impingement. These pathologies sometimes overlap. Untreated acetabular dysplasia of modest severity, if left uncorrected, always leads to arthrosis. Acetabular dysplasia is best treated by periacetabular osteotomy, usually combined with arthrotomy for management of labral pathology and associated cam-impingement, if present. Correction of deformities on the femoral side is now less common and reserved for only the more severe combined femoral and acetabular dysplasias or the rare isolated femoral dysplasia. Pre-operative variables associated with the best long-term outcomes include less secondary arthrosis, younger age, and concentric articular surfaces.

Femoroacetabular impingement has become progressively recognised as perhaps the most common cause of secondary arthrosis. The etiology of impingement is multifactorial and includes both genetic factors and stresses experienced by the hip prior to cessation of growth. Cam impingement can be quantified by the alpha angle as measured on plain radiographs and radial MR sequences. Further, significant cam impingement is clearly associated with the development of osteoarthrosis. Treatment can be performed either by arthroscopic or open femoral head-neck osteochondroplasty. As with hip dysplasia, prognosis following treatment is correlated with the severity of pre-operative secondary arthrosis but unfortunately impinging hips more commonly have some degree of arthrosis pre-op whereas dysplastic hips can become symptomatic with the onset of instability in the absence of significant secondary arthrosis. The scientific basis for the treatment of pincer impingement is less strong. Unlike cam impingement and hip dysplasia, pincer impingement pathology in the absence of coxa profunda has not been correlated with arthrosis and so rim trimming with labral refixation is probably performed more often than is clinically indicated. Similarly, caution should be exercised when considering rim-trimming for protrusion since high central contact pressures due to an enlarged acetabular notch are not corrected by rim trimming.

Overall, joint preserving surgery remains the preferred treatment for hips with mechanically correctable problems prior to the development of significant secondary arthrosis.

Femoroacetabular impingement (FAI) causes pain and chondrolabral damage via mechanical overload during movement of the hip. It is caused by many different types of pathoanatomy, including the cam ‘bump’, decreased head–neck offset, acetabular retroversion, global acetabular overcoverage, prominent anterior–inferior iliac spine, slipped capital femoral epiphysis, and the sequelae of childhood Perthes’ disease.

Both evolutionary and developmental factors may cause FAI. Prevalence studies show that anatomic variations that cause FAI are common in the asymptomatic population. Young athletes may be predisposed to FAI because of the stress on the physis during development. Other factors, including the soft tissues, may also influence symptoms and chondrolabral damage.

FAI and the resultant chondrolabral pathology are often treated arthroscopically. Although the results are favourable, morphologies can be complex, patient expectations are high and the surgery is challenging. The long-term outcomes of hip arthroscopy are still forthcoming and it is unknown if treatment of FAI will prevent arthrosis.

Our understanding of pre-arthritic hip disease has evolved tremendously but challenges remain in categorizing diagnosis, which ultimately impacts choice of treatments and clinical outcomes. This study aims to report patient reported outcome measures (PROMs) comparing four different condition groups within hip preservation surgery by a group of fellowship-trained surgeons. From 2018 to 2021, 380 patients underwent hip preservation surgery at our center and were classified into five condition groups: dysplasia: 82 (21.6%), femoro-acetabular impingement (FAI): 173 (45.4%), isolated labral tear: 103 (27.1%), failed hip preservation: 20 (5.3%) and history of childhood disease/other: 2 (0.5%). International hip outcomes Tool 12 (IHOT-12), numeric pain score and patient-reported outcomes measurement information system (PROMIS) were collected pre-operatively and at 3 months and 1 year post-operatively, with 94% and 82% follow-up rate respectively. Arthroscopy (75.5%) was the most common procedure followed by peri-acetabular osteotomy (PAO) (22.4%) and surgical dislocation (2.1%). Re-operation rate were respectively 18.3% (15), 5.8% (10), 4.9% (5), 30% (6) and 0%. There were 36 re-operations in the cohort, 14 (39%) for unintended consequences of initial surgery, 10 (28%) for mal-correction leading to a repeat operation, 8 (22%) progression of arthritis, and 4 (11%) for incorrect initial diagnosis/intervention. Most common re-operations were hardware removal 31% (7 PAO, 3 surgical hip dislocation and 1 femoral de-rotational osteotomy), arthroscopy 31% (11) and arthroplasty 28% (10). All groups had significant improvements in their IHOT-12 as well as PROMIS physical and numerical pain scales, except those with failed hip preservation. Dysplasia group showed a slower recovery. Overall, this study demonstrated a clear relation between the condition groups, their respective intervention and the significant improvements in PROMs with isolated labral pathology being a valid diagnosis. Establishing tertiary referral centers for hip preservation and longer follow-up is needed to monitor the overall survivorship of these various procedures

Aims. The Single Assessment Numerical Evalution (SANE) score is a pragmatic alternative to longer patient-reported outcome measures (PROMs). The purpose of this study was to investigate the concurrent validity of the SANE and hip-specific PROMs in a generalized population of patients with hip pain at a single timepoint upon initial visit with an orthopaedic surgeon who is a hip preservation specialist. We hypothesized that SANE would have a strong correlation with the 12-question International Hip Outcome Tool (iHOT)-12, the Hip Outcome Score (HOS), and the Hip disability and Osteoarthritis Outcome Score (HOOS), providing evidence for concurrent validity of the SANE and hip-specific outcome measures in patients with hip pain. Methods. This study was a cross-sectional retrospective database analysis at a single timepoint. Data were collected from 2,782 patients at initial evaluation with a hip preservation specialist using the iHOT-12, HOS, HOOS, and SANE. Outcome scores were retrospectively analyzed using Pearson correlation coefficients. Results. Mean raw scores were iHOT-12 67.01 (SD 29.52), HOS 58.42 (SD 26.26), HOOS 86.85 (SD 32.94), and SANE 49.60 (SD 27.92). SANE was moderately correlated with the iHOT-12 (r = -0.4; 95% CI -0.35 to -0.44; p < 0.001), HOS (r = 0.57; 95% CI 0.53 to 0.60; p < 0.001), and HOOS (r = -0.55; 95% CI -0.51 to -0.58; p < 0.001). The iHOT-12 and HOOS were recorded as a lower score, indicating better function, which accounts for the negative r values. Conclusion. This study was the first to investigate the relationship between the SANE and the iHOT-12, HOS, and HOOS in a population of patients with hip pain at the initial evaluation with an orthopaedic surgeon, and found moderate correlation between SANE and the iHOT-12, HOS, and HOOS. The SANE may be a pragmatic alternative for clinical benchmarking in a general population of patients with hip pain. The construct validity of the SANE should be questioned compared to legacy measures whose content validity has been more rigorously investigated. Cite this article: Bone Jt Open 2024;5(10):904–910

Aims. The frequency of severe femoral retroversion is unclear in patients with femoroacetabular impingement (FAI). This study aimed to investigate mean femoral version (FV), the frequency of absolute femoral retroversion, and the combination of decreased FV and acetabular retroversion (AR) in symptomatic patients with FAI subtypes. Methods. A retrospective institutional review board-approved observational study was performed with 333 symptomatic patients (384 hips) with hip pain due to FAI evaluated for hip preservation surgery. Overall, 142 patients (165 hips) had cam-type FAI, while 118 patients (137 hips) had mixed-type FAI. The allocation to each subgroup was based on reference values calculated on anteroposterior radiographs. CT/MRI-based measurement of FV (Murphy method) and AV were retrospectively compared among five FAI subgroups. Frequency of decreased FV < 10°, severely decreased FV < 5°, and absolute femoral retroversion (FV < 0°) was analyzed. Results. A significantly (p < 0.001) lower mean FV was found in patients with cam-type FAI (15° (SD 10°)), and in patients with mixed-type FAI (17° (SD 11°)) compared to severe over-coverage (20° (SD 12°). Frequency of decreased FV < 10° was significantly (p < 0.001) higher in patients with cam-type FAI (28%, 46 hips) and in patients with over-coverage (29%, 11 hips) compared to severe over-coverage (12%, 5 hips). Absolute femoral retroversion (FV < 0°) was found in 13% (5 hips) of patients with over-coverage, 6% (10 hips) of patients with cam-type FAI, and 5% (7 hips) of patients with mixed-type FAI. The frequency of decreased FV< 10° combined with acetabular retroversion (AV < 10°) was 6% (8 hips) in patients with mixed-type FAI and 5% (20 hips) in all FAI patients. Of patients with over-coverage, 11% (4 hips) had decreased FV < 10° combined with acetabular retroversion (AV < 10°). Conclusion. Patients with cam-type FAI had a considerable proportion (28%) of decreased FV < 10° and 6% had absolute femoral retroversion (FV < 0°), even more for patients with pincer-type FAI due to over-coverage (29% and 13%). This could be important for patients evaluated for open hip preservation surgery or hip arthroscopy, and each patient requires careful personalized evaluation. Cite this article: Bone Jt Open 2022;3(7):557–565

Aims. The primary aim of this study was to determine the ten-year outcome following surgical treatment for femoroacetabular impingement (FAI). We assessed whether the evolution of practice from open to arthroscopic techniques influenced outcomes and tested whether any patient, radiological, or surgical factors were associated with outcome. Methods. Prospectively collected data of a consecutive single-surgeon cohort, operated for FAI between January 2005 and January 2015, were retrospectively studied. The cohort comprised 393 hips (365 patients; 71% male (n = 278)), with a mean age of 34.5 years (SD 10.0). Over the study period, techniques evolved from open surgical dislocation (n = 94) to a combined arthroscopy-Hueter technique (HA + Hueter; n = 61) to a pure arthroscopic technique (HA; n = 238). Outcome measures of interest included modes of failures, complications, reoperation, and patient-reported outcome measures (PROMs). Demographic, radiological, and surgical factors were tested for possible association with outcome. Results. At a mean follow-up of 7.5 years (SD 2.5), there were 43 failures in 38 hips (9.7%), with 35 hips (8.9%) having one failure mode, one hip (0.25%) having two failure modes, and two hips (0.5%) having three failure modes. The five- and ten-year hip joint preservation rates were 94.1% (SD 1.2%; 95% confidence interval (CI) 91.8 to 96.4) and 90.4% (SD 1.7%; 95% CI 87.1 to 93.7), respectively. Inferior survivorship was detected in the surgical dislocation group. Age at surgery, Tönnis grade, cartilage damage, and absence of rim-trimming were associated with improved preservation rates. Only Tönnis grade was an independent predictor of hip preservation. All PROMs improved postoperatively. Factors associated with improvement in PROMs included higher lateral centre-edge and α angles, and lower retroversion index and BMI. Conclusion. FAI surgery provides lasting improvement in function and a joint preservation rate of 90.4% at ten years. The evolution of practice was not associated with inferior outcome. Since degree of arthritis is the primary predictor of outcome, improved awareness and screening may lead to prompt intervention and better outcomes. Cite this article: Bone Jt Open 2022;3(10):804–814

Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain. A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated. The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p<0.005). Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations