COVID-19 and the transition to virtual teaching sessions in an orthopaedic surgery training program: a survey of resident perspectives.

BACKGROUND: COVID-19 has had a tremendous impact on medical education. Due to concerns of the virus spreading through gatherings of health professionals, in-person conferences and rounds were largely cancelled. The purpose of this study is the evaluate the implementation of an online educational curriculum by a major Canadian orthopaedic surgery residency program in response to COVID-19. METHODS: A survey was distributed to residents of a major Canadian orthopaedic surgery residency program from July 10th to October 24th, 2020. The survey aimed to assess residents' response to this change and to examine the effect that the transition has had on their participation, engagement, and overall educational experience. RESULTS: Altogether, 25 of 28 (89%) residents responded. Respondents generally felt the quality of education was superior (72%), their level of engagement improved (64%), and they were able to acquire more knowledge (68%) with the virtual format. Furthermore, 88% felt there was a greater diversity of topics, and 96% felt there was an increased variety of presenters. Overall, 76% of respondents felt that virtual seminars better met their personal learning objectives. Advantages reported were increased accessibility, greater convenience, and a wider breadth of teaching faculty. Disadvantages included that the virtual sessions felt less personal and lacked dynamic feedback to the presenter. CONCLUSIONS: Results of this survey reveal generally positive attitudes of orthopaedic surgery residents about the transition to virtual learning in the setting of an ongoing pandemic. This early evaluation and feedback provides valuable guidance on how to grow this novel curriculum and bring the frontier of virtual teaching to orthopaedic education long-term.

The learning curve for the direct anterior total hip arthroplasty: a systematic review.

BACKGROUND: The direct anterior approach (DAA) for total hip arthroplasty (THA) is a muscle-sparing approach thought to have less post-operative pain and quicker recovery, with similar functional outcomes to other approaches. However, it is technically challenging and transitioning surgeons may experience increased complication rates. The purpose of this systematic review is to identify reported learning curves associated with the DAA. METHODS: Three databases (MEDLINE, Embase, and Web of Science) were searched using terms including "total hip arthroplasty," "direct anterior approach," and "learning curve." Study characteristics, patient demographics, learning curve analyses, and complications were abstracted. RESULTS: Twenty-one studies met inclusion criteria, with a total of 9738 patients (60% female), an average age of 63.7 years (range: 13-94), body mass index of 27.0 kg/m2 (range: 16.8-58.9), and follow-up of 19 months (range: 1.5-100). There were five retrospective cohort studies and 13 case series representing fair methodological quality. Six studies depicted a true learning curve, with mean operative time of 156.59 ± 41.71 minutes for the first case, 93.18 ± 14.68 minutes by case 30, and 80.45 ± 12.28 minutes by case 100. Mean complication rate was 20.8 ± 12.7% in early groups and decreased to 7.6 ± 7.1% in late groups. CONCLUSION: This review demonstrated a substantial learning curve associated with the DAA to THA. Operative time plateaued after approximately 100 cases. Complication rates decreased substantially from early to late groups.

Total knee arthroplasty using patient-specific instrumentation for osteoarthritis of the knee: a meta-analysis.

BACKGROUND: Total knee arthroplasty using patient-specific instrumentation (TKA-PSI), which are disposable cutting block guides generated to fit each patient's 3-dimensional knee anatomy, has been developed to treat patients with end-stage osteoarthritis of the knee. Surrogate markers such as radiographic malalignment have been well investigated, however, patient-important outcomes are not well examined to elucidate the efficacy of TKA-PSI. The aim of this review is to determine if TKA-PSI improves patient-reported outcome measures (PROM), surgery time, blood loss, transfusion and complications (e.g. surgical site infection, deep venous thrombosis, and revision TKA). METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and ongoing clinical trials. For PROMs, surgery time, blood loss, and transfusion rate, we included randomized controlled trials (RCT) comparing TKA-PSI and standard TKA to treat osteoarthritis of the knee. For complications, we also included non-randomized comparative studies (non-RCT). RESULTS: This review includes 38 studies, 24 of which were RCT and 14 of which were non-RCT. These included a total of 3487 patients. The predominant population in the included studies highly reflected the general population, with 62% being female, aged over 60 and having end-stage osteoarthritis of the knee. TKA-PSI did not improve PROMs as compared to standard TKA for less than 1-year (mean difference 0.48, 95% confidence interval (CI) -1.92-0.97 in the Oxford knee score, mean 3-month follow-up) and for 1-year or more (mean difference 0.25, 95%CI - 4.39-4.89 in the WOMAC score, mean 29-month follow-up). TKA-PSI did not reduce surgery time (mean difference - 3.09 min, 95%CI -6.73-0.55). TKA-PSI decreased blood loss with a small effect size corresponding to a 0.4 g/dl hemoglobin decrease (95%CI 0.18-0.88), but did not decrease transfusion rate (risk difference - 0.04, 95%CI -0.09-0.01). TKA-PSI did not reduce complication rates (risk difference 0.00, 95%CI - 0.01-0.01 in the composite outcome). CONCLUSIONS: TKA-PSI does not improve patient-reported outcome measures, surgery time, and complication rates as compared to standard TKA. TKA-PSI decreases blood loss with a small effect, which is not enough to reduce transfusion rate.

Indications and outcomes of simultaneous high tibial osteotomy and ACL reconstruction.

PURPOSE: The purpose of this study was to systematically review the existing literature reporting surgical outcomes of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament reconstruction (ACLR) in anterior cruciate ligament deficient (ACLD) knees. METHODS: This study was conducted per the methods of the Cochrane Handbook for Systematic Reviews of Intervention, with findings reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies and pertinent data was extracted. Studies reporting post-operative outcomes following simultaneous HTO and ACLR in ACLD knees were included. RESULTS: The search identified 515 studies, of which 18 (n = 516) were included. The mean MINORS scores for non-comparative and comparative studies were 11.6 ± 1.34 and 17.3 ± 1.9, respectively. Simultaneous HTO and ACLR resulted in improved functional subjective patient outcomes across a variety of scales. Simultaneous HTO and ACLR was effective in correcting varus angulation, with the post-operative mechanical angle ranging from 0.3° valgus to 7.7° valgus. The reported complication rate ranged from 0 to 23.5%. Across six studies, a total of 13 (6.5%) patients required revision HTO; while across four studies, 20 (17.5%) patients had failure of the ACL graft, with one receiving revision ACLR. CONCLUSIONS: Combined HTO and ACLR may be indicated in patients with ACLD knees with varus angulation. This systematic review found that the combined surgery resulted in significant improvement in post-operative functional subjective outcomes. However, it remains unclear if HTO with ACLR is superior to ALCR or HTO alone due to the lack of comparative studies. Overall, HTO with ACLR was found to have low rates of complications, re-ruptures, and need for revision surgery. This review found that patients continued to have progression of OA despite combined HTO with ACLR. Future research is required to better understand the effects of combined HTO and ACLR compared to ACLR or HTO alone and to evaluate the long-term post-operative progression of medial compartment OA following combined HTO and ACLR. LEVEL OF EVIDENCE: IV.

Preoperative Patient Factors Affecting Length of Stay following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Total knee arthroplasty (TKA) yields substantial improvements in quality of life for patients with severe osteoarthritis. Previous research has shown that TKA outcomes are inferior in patients with certain demographic and clinical factors. Length of stay (LOS) following TKA is a major component of costs incurred by healthcare providers. It is hypothesized that patient-related factors may influence LOS following TKA. The purpose of this systematic review and meta-analysis is to investigate these factors. METHODS: Three databases (PubMed, Embase, and OVID Medline) were searched using variants of the terms "total knee arthroplasty" and "length of stay". Studies were screened and data abstracted in duplicate. The primary outcome was the effect of prognostic variables on LOS following TKA. Meta-analysis was performed using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014). RESULTS: A total of 68 studies met all inclusion criteria for this review. These studies comprised 21,494,459 patients undergoing TKA with mean age 66.82 years (range, 15-95 years) and 63.8% (12,165,160 of 19,060,572 reported) females. The mean MINORS score was 7, suggesting that studies had a low quality of evidence. Mean LOS following TKA has steadily decreased over the past 4 decades, partially because of the implementation of fast-track programs. Demographic factors associated with increased LOS were age >70 years (mean difference [MD] = 0.81; 95% confidence interval [CI] = 0.38-1.24), female gender (MD = 0.32; 95% CI = 0.29-0.48), body mass index >30 (MD = 0.09; 95% CI = 0.01-0.16), and non-White race (MD = 0.20; 95% CI = 0.10-0.29). Clinical factors associated with increased LOS were American Society of Anesthesiologists score 3-4 vs 1-2 (MD = 1.12; 95% CI = 0.58 to 1.66), Charlson Comorbidity Index > 0 vs 0 (MD = 0.77; 95% CI = 0.32 to 1.22), and preoperative hemoglobin < 130 g/L (MD = 0.66; 95% CI = 0.34 to 0.98). CONCLUSION: This systematic review and meta-analysis showed that increased age, female gender, body mass index ≥ 30, non-White race, American Society of Anesthesiologists > 2, Charlson Comorbidity Index > 0, and preoperative hemoglobin < 130 g/L were predictors of increased LOS. Mean LOS has steadily decreased over the past decades with the implementation of perioperative "fast-track" programs. Future research should investigate the benefits of preoperative risk factor modification on LOS, in addition to novel surgical approaches, anesthetic adjuvants, and physiotherapy modifications. LEVEL OF EVIDENCE: IV, systematic review, and meta-analysis of level III and IV evidence.

Above knee amputation following total knee arthroplasty: when enough is enough.

In some cases, above knee amputation (AKA) for a chronically infected total knee arthroplasty is the only option. The purpose of this study was to assess patient satisfaction following AKA and to identify factors which may be indicative of successful outcome following AKA. A review was performed of 7 patients who underwent an AKA for a recurrent peri-prosthetic knee infection. Patient satisfaction was gauged through a modified questionnaire. All patients were satisfied with their AKA and 6 of 7 stated that they would have chosen an amputation earlier. Greater than 6 attempts at limb-salvage and failed gastrocnemius flap were identified by expert opinion as possible poor prognostic factors. Despite poor function, patients with chronically infected TKAs are satisfied following an AKA.

Hip arthroscopy: prevalence of intra-articular pathologic findings after traumatic injury of the hip.

PURPOSE: The purpose of this study was to document and compare the incidence of intra-articular hip pathologic findings identified using arthroscopy versus conventional imaging in patients with acute trauma to the hip. METHODS: This was a blinded prospective case series study designed to review the incidence of intra-articular pathologic disorders in patients with post-traumatic injury between the ages of 18 and 65 years who were referred to a single surgeon. Injuries included hip dislocation, proximal femur fracture, pelvic ring fracture, acetabular fracture, penetrating injury (gunshot wound), and soft tissue injury. Preoperative radiographs, computed tomographic (CT) scans, or magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) scans (or a combination of these) were obtained. Findings were documented and compared with intraoperative findings. RESULTS: A total of 29 post-traumatic hips were enrolled in this study. Hip arthroscopy identified 17 of 29 hips (59%) as having loose bodies, 11 of 29 (38%) hips as having an intra-articular step deformity, 14 of 29 (49%) hips as having an osteochondral lesion, and 27 of 29 (93%) hips as having a labral tear. Plain radiographs and CT scans yielded low sensitivity when compared with arthroscopy for the identification of loose bodies and step deformities. MRI/MRA comparison with arthroscopic findings suggest that MRI/MRA is an accurate tool for identification of labral tears, because 91% of tears seen on arthroscopy were also identified by MRI/MRA. In 4 hips, however, MRI/MRA failed to identify osteochondral lesions that were subsequently identified by arthroscopy. CONCLUSIONS: Traumatic injuries of the hip result in substantial intra-articular pathologic findings, including loose bodies, labral tears, step deformities, and osteochondral lesions. The arthroscope is a powerful tool in identifying these injuries. Plain radiographs and CT scans appear to underestimate the true incidence of loose bodies and step deformities within the joint when compared with hip arthroscopy after a traumatic injury of the hip. LEVEL OF EVIDENCE: Level IV, diagnostic case series.

Robot-assisted partial knee replacement versus standard total knee replacement (RoboKnees): a protocol for a pilot randomized controlled trial.

BACKGROUND: Total knee arthroplasty is a common surgery for end-stage knee osteoarthritis. Partial knee arthroplasty is also a treatment option for patients with arthritis present in only one or two knee compartments. Partial knee arthroplasty can preserve the natural knee biomechanics, but these replacements may not last as long as total knee replacements. Robotic-assisted orthopedic techniques can help facilitate partial knee replacements, increasing accuracy and precision. This trial will investigate the feasibility and assess clinical outcomes for a larger definitive trial. METHODS: This is a protocol for an ongoing parallel randomized pilot trial of 64 patients with uni- or bicompartmental knee arthritis. Patients are randomized to either receive robot-assisted partial knee arthroplasty or manual total knee arthroplasty. The primary outcome of this pilot is investigating the feasibility of a larger trial. Secondary (clinical) outcomes include joint awareness, return to activities, knee function, patient global impression of change, persistent post-surgical pain, re-operations, resource utilization and cost-effectiveness, health-related quality of life, radiographic alignment, knee kinematics during walking gait, and complications up to 24 months post-surgery. DISCUSSION: The RoboKnees pilot study is the first step in determining the outcome of robot-assisted partial knee replacements. Conclusions from this study will be used to design future large-scale trials. This study will inform surgeons about the potential benefits of robot-assisted partial knee replacements. TRIAL REGISTRATION: This study was prospectively registered on clinicaltrials.gov (identifier: NCT04378049) on 4 May 2020, before the first patient was randomized.

Return to Sport and Work Following Distal Femoral Varus Osteotomy: A Systematic Review.

Background: Distal femoral varus osteotomy (DFVO) is an effective surgical intervention for the management of symptomatic valgus malalignment of the knee. Because it preserves the native knee joint and its ligamentous stability, DFVO is preferred to total knee arthroplasty (TKA) in the young, active population. Purpose: We sought to assess return to work (RTW) and return to sport (RTS) rates following DFVO for valgus malalignment of the knee. Methods: For this systematic review, we searched EMBASE, MEDLINE, and Web of Science from inception through December 31, 2020. English language studies of all levels of evidence explicitly reporting on RTS and RTW rates following DFVO for valgus malalignment of the knee were eligible for inclusion. Results: Seven studies and 127 patients were included in our analysis. Mean age was 32.4 ± 8.8 years with men comprising 46.7% ± 22.3% of study populations. The mean RTS rate was 87.2% ± 10.7%, with a return to preoperative activity levels rate of 65.4% ± 26.8%. The mean RTW rate was 81.8% ± 23.3%, with a return to preoperative activity levels of 72.8% ± 18.1%. The mean reoperation rate was 35.6% ± 18.8% within a mean follow-up period of 5.5 ± 1.9 years. Conclusions: This systematic review of low-level studies found DFVO to be a safe and effective procedure for the management of genu valgum in young, active populations, with most patients returning to sport and/or work, although not all at their preoperative activity levels. A paucity of data surrounds RTS and RTW rates following DFVO. Future studies should explicitly report both return to activity rates and whether patients returned to their preoperative activity levels.

Antibiotic Cement in Arthroplasty: A Meta-analysis of Randomized Controlled Trials.

Introduction Periprosthetic joint infection (PJI) following arthroplasty surgery is a devastating complication. Antibiotic cement has been proposed as a way to reduce PJI rates. The aim of this systematic review and meta-analysis was to review all of the available randomized controlled trial (RCT) evidence on the use of antibiotic cement in arthroplasty. Methods PubMed, MEDLINE, and Embase were searched. All records were screened in triplicate. Eligible RCTs were included. Data regarding study characteristics, patient demographics, and rates of superficial and deep infection were collected. The risk of bias was assessed using the Cochrane Risk of Bias Assessment Tool 2.0. Results Five RCTs were included (n = 4,397). Four studies compared antibiotic cement to plain cement while one study compared high-dose dual-antibiotic (HDDA) cement to low-dose single-antibiotic (LDSA) cement. The mean age of included patients was 76.4 years (range: 68-83). There was no significant difference in superficial infection rates between antibiotic and plain cement (odds ratio (OR): 1.33, 95% Confidence Interval (CI): 0.77-2.30, p = 0.3). There was a large but non-significant reduction in deep infection rates for antibiotic cement (OR: 0.20, 95%CI: 0.03-1.32, p = 0.09). There was a significantly lower rate of infection with HDDA as compared to LDSA (OR: 0.31, 95% CI: 0.09-0.88, p = 0.041). Conclusion The available evidence from RCTs reveals a potential benefit for antibiotic cement in arthroplasty surgery, though this difference is non-significant and highly imprecise. Furthermore, HDDA cement was significantly more effective than LDSA cement. There is a need for large, pragmatic trials on this topic.

Knee osteoarthritis: when arthroscopy can help

Arthroscopic surgery of the knee is one of the most common orthopedic procedures performed globally. Recently, a lot of attention has been directed towards the role of arthroscopic surgery in the setting of osteoarthritis (OA) and its role in degenerative knee pathology. A number of recent randomized control trials and systematic reviews have suggested limited benefit for arthroscopic surgery and partial meniscectomy for this indication. With this recent focus on the use of arthroscopy in OA, it is often forgotten that arthroscopy plays an important role in the management of other pathologies involving the knee in patients who may have a concomitant diagnosis of OA. This evidence­based review highlights indications for when arthroscopic intervention is warranted in such patients.

Cement Waste During Primary Total Knee Arthroplasty and its Effect on Cost Savings: An Institutional Analysis.

Purpose Healthcare costs are increasingly garnering more media attention and there is increasing focus on improving efficiencies in daily practice. Orthopedic surgery is also subject to these fiscal pressures, particularly in arthroplasty surgeries, secondary to high volumes with costly equipment. Total knee arthroplasties (TKA) are one of the most common surgical procedures, with over 64,000 annual cases in Canada. Even marginal cost reductions per procedure can be compounded over the large volume to result in considerable savings. This study's purpose is to investigate and quantify the cost of wasted intraoperative cement used in primary TKA. Methods Residual amounts of wasted bone cement were collected and measured following uncomplicated primary TKAs performed by the senior authors in a high-volume arthroplasty centre between January and June 2017. Stryker Simplex® with Tobramycin Bone Cement was the specific institutional cement used. Results One hundred and two primary total knee arthroplasties were investigated. The results revealed that an average 91.2 g of surgical cement was wasted per case, with less than 30 g retained in the bone-implant interface (26.8 g). Institutional costs per package of cement is $120.62, amounting to $2.04 per gram of cement. This represents a value of $186.25 CAD per case. Conclusion On average, each primary TKA procedure wastes 91.2 g of bone cement per case. The value of this wasted cement is $186.25 CAD per TKA. When extrapolated to the most recent recorded numbers of TKAs done in Canada, that figure nears $12 million. The results of this study are important, as they reveal a potential source to target for both waste reduction and cost control.

Nonoperative Treatments for Knee Osteoarthritis: An Evaluation of Treatment Characteristics and the Intra-Articular Placebo Effect: A Systematic Review.

BACKGROUND: Guidelines recommending various nonoperative treatments for patients with knee osteoarthritis remain inconsistent. Much of this controversy relates to what constitutes a clinically important effect. The purposes of the present study were to compare treatment effect sizes from recent meta-analyses evaluating pharmacological or medical device interventions for the treatment of knee osteoarthritis and to further assess the clinical impact that the intra-articular placebo effect may have on intra-articular injection therapies. METHODS: A search of PubMed, MEDLINE, and Embase from the inception date of each database through May 30, 2017 was conducted for all articles involving meta-analyses of pharmacological or medical device knee osteoarthritis treatments compared with controls. Two reviewers independently screened articles for eligibility and extracted data for analysis. We present effect estimates on a standardized mean difference (SMD) scale and compare them all against a threshold for clinical importance of 0.50 standard deviation (SD) unit. RESULTS: Ten meta-analyses (sample size range, 110 to 39,814) providing a total of 19 different effect sizes for pain were included in this review. SMD estimates ranged from 0.08 to 0.79 for various electrical modalities, orthotic devices, topical and oral nonsteroidal anti-inflammatory drugs (NSAIDs), dietary supplements, and intra-articular injection therapies. Seventeen treatments demonstrated significant improvements in terms of pain when patients who had received treatment were compared with controls. After accounting for the intra-articular placebo effect, the greatest effect estimates were those of intra-articular platelet-rich plasma and high molecular weight hyaluronic acid. When these were judged according to our threshold for clinical importance, high molecular weight intra-articular hyaluronic acid was found to have the most precise effect estimate that surpassed this threshold. Platelet-rich plasma was found to provide the greatest point estimate of the treatment effect, but the precision around this estimate had the largest amount of uncertainty across all treatments. CONCLUSIONS: While many nonoperative treatments demonstrated significant improvements in pain, we found the greatest effect estimates for intra-articular treatments. While platelet-rich plasma provided the greatest point estimate of the treatment effect, variability among studies suggests that future research into optimal formulations is required. The strongest current evidence supports clinically important and significant treatment effects with intra-articular hyaluronic acid formulations between 1,500 and >6,000 kDa. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Perioperative systemic glucocorticoids in total hip and knee arthroplasty: A systematic review of outcomes.

BACKGROUND: Perioperative systemic glucocorticoids are frequently included in multimodal analgesia and antiemetic regimens administered to patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The objective of this systematic review was to evaluate the available randomized controlled trials (RCTs) to determine the effect of perioperative systemic glucocorticoids on postoperative nausea and vomiting (PONV), pain, narcotic consumption, antiemetic consumption, length of stay in hospital, and major complications in patients undergoing elective THA or TKA. METHODS: A predefined protocol of eligibility and methodology was used for conduct of systematic reviews. Two reviewers screened citations for inclusion, assessed methodological quality, and verified the extracted data. RESULTS: Six RCTs were included for analysis. Across all outcomes analyzed, patients who received glucocorticoids experienced either a benefit or no difference compared to those patients who did not receive glucocorticoids. There were no instances in which perioperative glucocorticoids had a negative impact on any of the outcomes that were analyzed. Furthermore, perioperative glucocorticoids had no effect on the rates of superficial infection, deep infection, wound complications or deep vein thrombosis (DVT). CONCLUSION: The results of this systematic review support the use of perioperative systemic glucocorticoids in patients undergoing elective total hip and knee arthroplasty. Perioperative glucocorticoids have overall positive outcomes with the benefits being more robust in those patients undergoing TKA compared to THA. Glucocorticoids did not increase the occurrence of major complications. There is limited data to support the conclusion that they can reduce length of stay in hospital.

Does the femoral head/neck contour in the skeletally mature change over time?

The purpose of this study was to determine whether anterior/anterolateral femoral head/neck contour of the hip is static or dynamic over time within the context of the cam deformity. From a previously published cohort of 200 asymptomatic patients who had a magnetic resonance imaging (MRI) of their hips, 23 patients were randomly selected: 10 with a cam lesion and 13 with no evidence of a cam lesion in either hip. There were 7 females and 16 males with a mean age of 37.5 years (range 30-56 years). A repeat MRI or computed tomography scan was performed. Femoral head/neck contour was assessed with alpha angle measurements at the 3 and 1:30 positions. At mean time of 5.3 years (range 2.5-7.2 years) between the two time points, the mean alpha angle for the entire cohort was not significantly different with alpha angle of 43.4°/53.7° (3:00/1:30 positions) at first visit and 46.1°/54.2° (3:00/1:30 positions) at second visit, respectively. Subdividing the cohort into cam negative and cam positive groups, there are no clinically relevant differences (i.e. <5°) between the two alpha angle measurements. Inter-observer reliability had an intra-class coefficient at 0.96 (95% CI: 0.94-0.97). Neither group of patients demonstrated clinically relevant change in the alpha angle. Consequently, screening at time of skeletal of maturity would be an efficient means of identifying individuals for a possible cam deformity.

Defining structural abnormalities of the hip joint at risk of degeneration.

The purpose of this review is to explore the mounting evidence that primary osteoarthritis is secondary to childhood disorders such as dysplasia and/or to subtle morphologic and structural to subtle morphologic and structural abnormalities of the proximal femur and/or acetabulum that were previously unrecognized or underestimated. These structural deformities lead to early impingement through range of motion and subsequent joint degeneration. The review also presents a brief synopsis of the genetic components that influence structural morphology of the hip joint and the impact of genetic pathways on OA development. If subtle deformities can be shown to be effective predictors of OA in the general population, it may be possible to identify hips that are at risk before they progress to end-stage OA. Furthermore, if these early risk factors are modifiable, it may be possible to implement preventative measures before the requirement of total hip arthroplasty.

Incidence of hip pain in a prospective cohort of asymptomatic volunteers: is the cam deformity a risk factor for hip pain?

BACKGROUND: Although cam-type femoroacetabular impingement is commonly associated with labral chondral damage and hip pain, a large proportion of asymptomatic individuals will have this deformity. PURPOSE: To determine the incidence of hip pain in a prospective cohort of volunteers who had undergone magnetic resonance imaging (MRI) of their hips. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: A total of 200 asymptomatic volunteers who underwent an MRI of both hips were followed for a mean time of 4.4 years (range, 4.01-4.95 years). Thirty were lost to follow-up, leaving 170 individuals (77 males, 93 females) with a mean age of 29.5 years (range, 25.7-54.5 years). All patients were blinded to the results of their MRI. All completed a follow-up questionnaire inquiring about the presence of hip pain or a history of hip pain lasting longer than 6 weeks since the original MRI. Each patient was asked to draw where the pain was on a body diagram. RESULTS: Eleven patients (5 males, 6 females; 6.5% of sample; mean age, 29.9 years; range, 25.7-45.6 years) reported hip pain, of which 3 (1 male, 2 females) had bilateral pain for a total of 14 hips. Seven of the 14 painful hips had a cam-type deformity at the time of the initial MRI versus 37 of the 318 nonpainful hips (P = .0002). This gave a relative risk of 4.3 (95% confidence interval [CI], 2.3-7.8) of developing hip pain if cam deformity was present. Those 14 painful hips had a significantly greater alpha angle at the radial 1:30 clock position than did those who did not develop pain with a cam deformity: 61.5° (range, 57.3°-65.7°) versus 57.9° (range, 56.9°-59.1°), respectively (P = .05). A significantly greater proportion of patients (12%) with limited internal rotation ≤20° (versus 2.7% with internal rotation >20°) went on to develop hip pain (P = .009; relative risk = 3.1 [95% CI, 1.6-6.0]). CONCLUSION: The presence of a cam deformity represents a significant risk factor for the development of hip pain. An elevated alpha angle at the 1:30 clock position and decreased internal rotation are associated with an increased risk of developing hip pain. However, not all patients with a cam deformity develop hip pain, and further research is needed to better define those at greater risk of developing degenerative symptoms.