MLK3 mediates impact of PKG1α on cardiac function and controls blood pressure through separate mechanisms

cGMP-dependent protein kinase 1α (PKG1α) promotes left ventricle (LV) compensation after pressure overload. PKG1-activating drugs improve heart failure (HF) outcomes but are limited by vasodilation-induced hypotension. Signaling molecules that mediate PKG1α cardiac therapeutic effects but do not promote PKG1α-induced hypotension could therefore represent improved therapeutic targets. We investigated roles of mixed lineage kinase 3 (MLK3) in mediating PKG1α effects on LV function after pressure overload and in regulating BP. In a transaortic constriction HF model, PKG activation with sildenafil preserved LV function in MLK3+/+ but not MLK3-/- littermates. MLK3 coimmunoprecipitated with PKG1α. MLK3-PKG1α cointeraction decreased in failing LVs. PKG1α phosphorylated MLK3 on Thr277/Ser281 sites required for kinase activation. MLK3-/- mice displayed hypertension and increased arterial stiffness, though PKG stimulation with sildenafil or the soluble guanylate cyclase (sGC) stimulator BAY41-2272 still reduced BP in MLK3-/- mice. MLK3 kinase inhibition with URMC-099 did not affect BP but induced LV dysfunction in mice. These data reveal MLK3 as a PKG1α substrate mediating PKG1α preservation of LV function but not acute PKG1α BP effects. Mechanistically, MLK3 kinase-dependent effects preserved LV function, whereas MLK3 kinase-independent signaling regulated BP. These findings suggest augmenting MLK3 kinase activity could preserve LV function in HF but avoid hypotension from PKG1α activation.

Incorporating Hip Arthroscopy Into A Practice

Hip arthroscopy is one of the most rapidly growing areas in orthopaedic surgery because of increased awareness of nonarthritic hip pathologies, advanced imaging modalities, and advanced techniques to reproducibly manage nonarthritic hip pathologies within a deep soft-tissue envelope and a constrained joint. In addition, more academic medical centers are providing residents with education on hip arthroscopy, and many hip preservation fellowships and courses are helping increase awareness of nonarthritic hip pathologies. Nonarthritic hip pathologies currently managed via hip arthroscopy include nonrepairable labral lesions, femoroacetabular impingement, hip instability, and hip fractures. Periarticular hip pathologies currently managed via endoscopy include greater trochanteric pain syndrome, tendinopathy and tears of the gluteus medius and minimus, partial and complete hamstring avulsions, and sciatic nerve entrapment. Ischiofemoral impingement may be addressed endoscopically via the deep gluteal space. Orthopaedic surgeons should understand the role and safety of hip arthroscopy in the pediatric population, specifically in the management of slipped capital femoral epiphysis, Legg-Calvé-Perthes disease, and septic arthritis of the hip. The efficacy of hip arthroscopy is limited, and hip arthroscopy is relatively contraindicated in patients with osteoarthritis and hip dysplasia. Complications can occur and likely are underreported in patients who undergo hip arthroscopy. Orthopaedic surgeons should understand practical issues associated with incorporating hip arthroscopy into a practice, including the difficult learning curve associated with hip arthroscopy and the reluctance of some payors to reimburse procedures performed arthroscopically because hip arthroscopy is a relatively new technology.

Short-Term Administration of Serelaxin Produces Predominantly Vascular Benefits in the Angiotensin II/L-NAME Chronic Heart Failure Model

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Temporary administration of recombinant relaxin-2 (serelaxin) in patients hospitalized with HF was associated with improved mortality 6 months after discharge.

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The specific effects of serelaxin on vascular and myocardial structure and function in HF have not been studied.

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In mice subjected to continuous 28-day heart failure stimulus of AngII and L-NAME, serelaxin was administered for 3 days (days 7 to 9), and both the acute effects during serelaxin infusion and the delayed effects after termination of serelaxin on cardiovascular structure and function were studied.

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Temporary serelaxin improved vascular fibrosis and myocardial capillary density and reduced resistance vessel constriction to potassium chloride during administration. These effects unexpectedly persisted 19 days after discontinuation of serelaxin, despite continued exposure to AngII/L-NAME. Serelaxin did not alter cardiac hypertrophy, geometry, or dysfunction at either time point.

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These findings support that serelaxin predominantly affects vascular structure and function in the setting of HF.

In patients hospitalized with acute heart failure, temporary serelaxin infusion reduced 6-month mortality through unknown mechanisms. This study therefore explored the cardiovascular effects of temporary serelaxin administration in mice subjected to the angiotensin II (AngII)/L-NG-nitroarginine methyl ester (L-NAME) heart failure model, both during serelaxin infusion and 19 days post–serelaxin infusion. Serelaxin administration did not alter AngII/L-NAME-induced cardiac hypertrophy, geometry, or dysfunction. However, serelaxin-treated mice had reduced perivascular left ventricular fibrosis and preserved left ventricular capillary density at both time points. Furthermore, resistance vessels from serelaxin-treated mice displayed decreased potassium chloride–induced constriction and reduced aortic fibrosis. These findings suggest that serelaxin improves outcomes in patients through vascular-protective effects.

Do Neuromuscular Alterations Exist for Patients With Acetabular Labral Tears During Function?

PURPOSE

To determine if contact forces and electromyography (EMG) muscle amplitudes were altered during the lunge for patients with symptomatic labral tears compared with asymptomatic control subjects.

METHODS

Surface electromyography electrodes were placed over the gluteus medius, gluteus maximus, adductor longus, and rectus femoris muscles of the patients' involved limb and matched limb of asymptomatic controls. Subjects performed 3 trials of the lunge on a clinical force platform. An electrogoniometer tracked knee flexion motion during testing. Average root mean squared EMG muscle amplitudes for each muscle were calculated for the descent and ascent phases of the lunge, represented as a percentage of maximum activity (%MVIC). Peak knee flexion was calculated from the goniometer (°). The dependent variables from the force platform were lunge distance (%height), contact time (seconds), vertical impact force (%BW), and force impulse (%BW*s). Dependent variables were compared between groups using either independent samples t tests or Mann-Whitney U tests. Relations between dependent variables were assessed with Spearman Rho correlation coefficients. The level of significance was set at P ≤ .05.

RESULTS

Twenty-one patients with symptomatic unilateral labral tears (14 females, 7 males) and 17 asymptomatic control subjects (11 females, 6 males) participated in this study. Average gluteus maximus EMG muscle amplitudes were reduced for symptomatic labral patients compared with asymptomatic controls during lunge ascent (51.6 ± 31.1 v 71.7 ± 36.3 [mean difference (MD): 20.1% (-2.4%, 42.6%)], P = .042). Average vertical impact force was reduced (21.8 ± 5.5 v 26.8 ± 7.3 [MD: 5.1%BW (0.84%BW, 9.3%BW)], P = .02) and average contact time (1.8 ± 0.4 v 1.5 ± 0.4 [MD: 0.27 seconds (0.006 seconds, 0.54 seconds)], P = .045) and force impulse (188.4 ± 42.4 v 162.6 ± 33.3 [MD: 25.8%BW*s (0.3%BW*s, 51.4%BW*s)], P = .042) were increased for symptomatic labral patients compared with asymptomatic controls. Vertical impact force was inversely correlated with gluteus medius muscle amplitudes during lunge descent for symptomatic labral patients (r = -0.452, P = .045).

CONCLUSIONS

Our study shows that contact forces and EMG muscle amplitudes are altered during the lunge for patients with symptomatic labral tears. The presence of a relation between muscle amplitudes and contact forces suggests that targeting muscle impairments may restore function in these patients.

LEVEL OF EVIDENCE

Level III, case-control study.

Cartilage Status at Time of Arthroscopy Predicts Failure in Patients With Hip Dysplasia

The purpose of our study was to determine whether chondral damage at the time of arthroscopy predicted conversion to THA in patients with dysplasia. We identified 166 patients with dysplasia who underwent hip arthroscopy. Forty-seven went on to receive THA. The articular cartilage of three regions of the acetabulum and femoral head were assessed for signs of chondral damage (absent, mild, or severe]). A stepwise multivariable logistic regression analysis revealed mild damage on the posterior femoral head (P=0.001) and severe damage on the anterior acetabulum (P=0.007) made a significant contribution to the predictor. The presence of mild posterior femoral head chondral changes was indicative of more global cartilage damage in this series of patients. Our findings show that chondral damage on the posterior femoral head and anterior acetabulum is a strong predictor of ultimate conversion to THA in dysplastic patients.

Assessing outcomes following arthroscopic labral debridement-what can the IHOT-33 reveal?

As the complexity of arthroscopic procedures continues to increase, assessing the success of these procedures is of utmost importance to determine appropriate treatment plans for patients. This study compares outcome scores on the International Hip Outcome Tool (IHOT-33) using an analysis of its four subscales to scores on the Modified Harris Hip Score (MHHS) in patients following hip arthroscopy. Patients who had undergone hip arthroscopy between 1 and 5 years ago were assessed using both the IHOT-33 and MHHS at their most recent follow-up visit. Total scores for each outcome measure were calculated. A composite score for each of the IHOT subscales was calculated by averaging the total points in each section. Total score on the MHHS was compared with total score on the IHOT-33 and its four subscales using separate wilcoxin signed ranks tests. In total, 44 patients met our inclusion criteria with an average follow-up of 24.8 ± 18.8 months. MHHS total score was greater than IHOT-33 total score (P = 0.04). Comparisons between MHHS total score and the IHOT-33 subscales revealed reductions in sport (P = 0.001) and social (P = 0.004), but no difference in symptoms (P = 0.74) and job (P = 0.84). Our findings demonstrated that scores on the MHHS are inflated when compared with scores on the IHOT-33 for patients following hip arthroscopy. Subscale analysis revealed that the reductions in IHOT-33 scores exist in the sport and recreational domain and social, emotional, lifestyle domain compared with the MHHS. Our results suggest that analysing the subscales of the IHOT-33 would provide a more thorough understanding of functional limitations in patients undergoing hip arthroscopy.

Preoperative erythropoietin alpha reduces postoperative transfusions in THA and TKA but may not be cost-effective

BACKGROUND

Preoperative erythropoietin alpha (EPO) has been shown to be effective at reducing postoperative blood transfusions in total hip arthroplasty (THA) and total knee arthroplasty (TKA); however, treatment with EPO is associated with additional costs, and it is not known whether these costs can be justified when weighed against the transfusion reductions achieved in patients who receive the drug.

QUESTIONS/PURPOSES

The purpose of this study is to investigate (1) efficacy of preoperative EPO in reducing postoperative transfusions in TKA and THA; (2) whether patients treated with EPO have reduced length of stay or a different discharge disposition; and (3) whether EPO use reduces overall blood management costs.

METHODS

Patients undergoing primary THA or TKA over a 10-month period with preoperative hemoglobin<13 g/dL were recommended to be treated preoperatively with EPO. During that time, 80 of 286 (28%) patients met that inclusion criterion and the treating team recommended EPO to all of them; of that group, 24 (30%) opted to take EPO and 56 (70%) opted not to. Patients receiving at least one dose of EPO and those not receiving EPO were compared in terms of transfusion frequency, length of stay and discharge disposition, and overall blood management costs. Demographics, preoperative hemoglobin, and operative blood loss for both groups were similar (p>0.05). No transfusion triggers were used; rather, patients with postoperative hemoglobin<10 mg/dL and who were symptomatic despite fluid boluses were transfused. The clinician responsible for transfusing symptomatic patients was blinded to the patient's EPO treatment status. Costs were defined as direct costs paid or incurred by our institution for EPO, allogeneic blood, and variable costs associated with patient care after THA/TKA. A decision-tree cost analysis was performed using the collected clinical data and cost data collected from our institution; the analysis considered total associated blood management cost for an EPO and a non-EPO strategy with sensitivity analysis of key cost variables.

RESULTS

The proportion of patients receiving transfusions was lower in patients who received EPO than in patients who did not (0% [zero of 24] versus 41% [23 of 56]; p<0.001). The mean length of inpatient hospital stay (EPO: 3.0±0.4 versus control: 3.3±0.8 days, p=0.77) and discharge disposition also was not different between the groups. The cost analysis demonstrated that the EPO strategy was more costly compared with no EPO (USD 2632 versus USD 2284) and its cost would need to be less than USD 225/dose for this to change.

CONCLUSIONS

EPO reduced the need for postoperative transfusions in high-risk patients undergoing THA and TKA; however, it was not found to be cost-effective in our model. Our model could not consider relatively rare complications of blood transfusions, including disease transmission, deep periprosthetic infections, and transfusion reactions, but if surgeons or patients value avoiding these potential but rare factors highly, this could reasonably influence the decision of whether to use EPO despite our findings that it was not cost-effective.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Femoroacetabular impingement negates the acetabular labral seal during pivoting maneuvers but not gait

BACKGROUND

Experimental disruption of the labrum has been shown to compromise its sealing function and alter cartilage lubrication. However, it is not known whether pathological changes to the labrum secondary to femoroacetabular impingement (FAI) have a similar impact on labral function.

QUESTIONS/PURPOSES

Does damage to the labrum occurring in association with abnormal femoral morphology affect the labral seal?

METHODS

Using 10 fresh cadaveric specimens (mean age 50 years, ±8), we measured the capacity of the central compartment of the hip (the iliofemoral joint) to maintain a seal during fluid infusion, which may help elucidate the function of the labrum during weightbearing. Specimens with and without abnormal femoral morphology (six normal-appearing specimens and four whose geometry suggested cam-type FAI) were tested in postures observed during functional activities, including simulations of normal gait, stooping, and pivoting. Each specimen with FAI morphology exhibited secondary damage of the labrum and the adjacent chondral surface, whereas specimens of normal morphology were undamaged.

RESULTS

Average peak central compartment pressure was reduced during pivoting for specimens with the presence of labral damage secondary to FAI. When placed in pivoting positions, hips with FAI maintained lower fluid pressures within the central compartment compared with intact specimens (15±3 versus 42±8 kPa, respectively; effect size: 1.08 [-0.36 to 2.31]; p=0.007). No differences in peak pressure were observed between groups (FAI versus normal) for postures simulating either gait (21±6 versus 22±4 kPa; p=0.902) or stooping (9±2 versus 8±3 kPa; p=0.775) with the numbers available.

CONCLUSIONS

The acetabular seal, quantified by the maximum intraarticular pressure, was reduced during pivoting; however, the seal was maintained during simulated gait and stooping.

CLINICAL RELEVANCE

Because degeneration is progressive with repetitive impingement, loss of the labral seal starts to be seen during pivoting and may progress from there, but in this small-sample cadaver study that evaluated specimens in middle adulthood, the seal remains intact during simulated gait and stooping. Our study suggests that labral damage secondary to cam-type FAI may reduce the ability of the labral to provide an adequate seal of the central compartment of the hip during loading; however, the extent to which this is affected requires further investigation.

The acetabular labrum regulates fluid circulation of the hip joint during functional activities

BACKGROUND

An assessment of the effect of surgical repair or reconstruction on the function of the hip labrum is critical to the advancement of hip preservation surgery; however, validated models of the hip that allow the quantification of labral function in functional joint positions have yet to be developed.

PURPOSE

To evaluate (1) whether intra-articular pressures within the hip are regulated by fluid transport between the labrum and femoral head and (2) whether the sealing capacity of the labrum varies with joint posture.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The sealing ability of the hip labrum was measured during fluid infusion into the central compartments of 8 cadaveric specimens. Additionally, the pathway of fluid transfer from the central to the peripheral compartment was assessed via direct visualization in 3 specimens. The effect of joint posture on the sealing capacity of the labrum was determined by placing all 8 specimens in 10 functional postures. The relationship between pressure resistance and 3-dimensional motion of the femoral head within the acetabulum was quantified using motion analysis and computer modeling.

RESULTS

Resistance to fluid transport from the central compartment of the hip was directly controlled by the labrum during loading. Maximum pressure resistance was affected by joint posture (P = .001). Specifically, positions that increased external rotation of the joint (pivoting) provided an improved seal, while positions that increased flexion combined with internal rotation (stooping) augmented the ease of fluid transport from the central to the peripheral compartment. Maximum pressure resistance was associated with the distance between the labrum and femoral head during pivoting.

CONCLUSION

This study demonstrated that the transfer of fluid from the central compartment of the hip occurs at the junction of the labrum and femoral head. Joint position was shown to strongly affect the sealing function of the labrum and was attributable to the distance between the labrum and femoral head in certain positions.

CLINICAL RELEVANCE

Altering the relationship between the labrum and femoral head may disrupt the sealing ability of the labrum, potentially leaving the joint at risk for pathological changes with time.

Hip pain in the young, active patient: surgical strategies

Hip disorders in young patients likely exist as a spectrum of prearthritic and arthritic conditions. With the increasing recognition of these disorders, surgical options are being popularized and more patients are being treated at a younger age. Hip surgeons must develop a careful set of evidenced-based indications and follow surgical outcomes in a rigorous, scientific manner. Hip arthroscopy can be used to successfully treat some hip disorders, including labral tears, with or without femoroacetabular impingement, resulting in mechanical symptoms. Long-term outcomes after arthroscopy are determined by the condition of the cartilage at the time of surgery. Patients with preoperative radiographic evidence of moderate to severe arthritis have poor outcomes when treated with arthroscopy. Open joint preservation procedures (including periacetabular osteotomy and surgical hip dislocation with osteochondroplasty) can be done in the absence of substantial arthritis to treat hip dysplasia, femoroacetabular impingement, and related conditions. The results of these procedures are good in appropriately selected patients at short-term to midterm follow-ups. In the presence of severe arthritis, joint replacement is the treatment of choice. Total hip arthroplasty using uncemented acetabular and femoral fixation provides reliable osseointegration; however, long-term results in young patients have historically been compromised by bearing surface wear, osteolysis, and component loosening. Contemporary, highly cross-linked polyethylene and ceramic-on-ceramic bearings have durable results, low complication rates, and offer the potential of long-term survivorship in this high-demand population. In general, metal-on-metal implants have higher complication rates versus other bearing surface options and should be avoided. The best results of hip resurfacing are seen in men younger than 55 years with large femoral head sizes. Although implant survivorship is comparable to that of total hip arthroplasty, the sequelae of metal wear debris continue to cause concern.

Correlation of magnetic resonance arthrography with revision hip arthroscopy

BACKGROUND

Arthroscopic approaches for the diagnosis and treatment of hip disorders are well established; however, there are limited data regarding revision hip arthroscopy. There have been several studies evaluating the findings of MR arthrography with primary hip arthroscopy, but to our knowledge, no study has evaluated the diagnostic value of MR arthrography before revision hip arthroscopy.

QUESTIONS/PURPOSES

We obtained sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MR arthrography to detect labral lesions, chondral lesions and loose bodies before revision hip arthroscopy.

METHODS

We performed a single-surgeon, retrospective review of 70 revision hip arthroscopies (62 patients) and assessed the association between MR arthrography findings and intraoperative findings. There were 43 females and 19 males with a mean age of 36 years (range, 17-59 years). Radiographic interpretation was performed by one of four fellowship-trained musculoskeletal radiologists at three institutions, who had at least 5 years of experience. Radiographic findings were compared with surgical findings by one of the authors for calculation of sensitivity, specificity, PPV, and NPV.

RESULTS

The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting labral tears were 82%, 70%, 94%, and 39%, respectively. The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting chondral damage were 65%, 90%, 94%, and 50%, respectively. The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting loose bodies were 33%, 100%, 100%, and 88%, respectively.

CONCLUSIONS

Our study showed the utility of MR arthrography to assist in the diagnosis and treatment of patients with ongoing or recurrent symptoms who have had prior hip arthroscopy. Our data show that MR arthrography is superior at ruling in, rather than ruling out, labral lesions, chondral lesions, and loose bodies, as there were studies interpreted as normal which in fact showed disorders.

Ankle fracture following hip arthroscopy

This article describes a case of an ankle fracture following hip arthroscopy. A 58-year-old woman underwent hip arthroscopy for a labral tear. She was placed in a lateral decubitus position with her foot in a padded boot. Traction was maintained for approximately 30 minutes. She was instructed to bear weight as tolerated with crutches postoperatively. At 2-week follow-up, she reported ipsilateral ankle pain. Radiographs revealed a minimally displaced medial malleolus fracture. She was treated with a cast followed by a cam walker boot and successfully went on to complete union and resolution of her symptoms. The following risk factors exist for ankle fracture after hip arthroscopy: history of ankle sprains, ligamentous laxity (more common in women), and small feet with large calves (more likely to become plantarflexed during traction). Distraction performed with the ankle rotated is also likely to place added stress on the medial or lateral ligamentous structures. It is important to counsel patients preoperatively about the risk of ankle pain after hip arthroscopy, to be aware of the possibility of ankle pathology postoperatively, and to have a low threshold for ordering radiographs. Radiographs are warranted if patients continue to have ankle pain after 72 hours postoperatively.

Technical pearls for hip arthroscopy in the management of synovial chondromatosis

Synovial chondromatosis of the hip is often underdiagnosed. A high index of suspicion and good quality imaging studies are therefore essential. A wide array of long and curved instrumentation is needed at surgery. Efficient use of time and an organized surgical approach are critical to decrease joint distraction time and potential complications. A successful outcome, with pain relief and return of joint function and range of motion, is predicated on incremental follow-up.

A resident survey study of orthopedic fellowship specialty decision making and views on arthroplasty as a career

A dramatic shortage of total hip arthroplasty (THA) and total knee arthroplasty (TKA) surgeons has been projected because fewer residents enter arthroplasty fellowships, and the demand for THAs/TKAs is rising. The purposes of this study were to ascertain the future supply of THA/TKA surgeons, to identify the criteria residents use to choose their fellowship specialty, and to assess resident perceptions of an arthroplasty career. Four hundred ninety-eight post-graduate year 3 and above residents completed the online survey. Residents most highly prioritize intellectual factors and role models/mentors in determining their fellowship specialty. In the face of a looming patient access-to-care crisis, the data from this study support a policy of highlighting the intellectual challenges and satisfaction of THA/TKA as a career and encouraging mentorship early in a resident's training.

Efficacy of hip arthroscopy in the management of synovial chondromatosis

BACKGROUND

Synovial chondromatosis can result in intra-articular loose bodies. Open arthrotomy has been the conventional treatment for this condition in the hip. Hip arthroscopy, however, is a minimally invasive approach and avoids potential problems with open arthrotomy.

PURPOSE

This series was described to evaluate the role of arthroscopy in treatment and outcome of synovial chondromatosis of the hip at early to intermediate follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-nine patients had arthroscopic treatment for synovial chondromatosis of the hip. All loose bodies were intracapsular and smaller than 10 mm. Radiographs of the painful hip, computed tomography (CT), and gadolinium-enhanced magnetic resonance imaging (MRI) were obtained preoperatively. Intraoperatively, loose bodies were removed, and partial synovectomy, partial labrectomy, chondroplasty, and microfracture were done as needed.

RESULTS

There were 14 women and 15 men (mean age, 41 years; mean duration of symptoms, 52 months). All patients had hip pain and 63% reported mechanical hip symptoms. Twenty-three patients were followed for at least 12 months (mean, 64 months). Loose bodies could be seen in the imaging studies of 52% of patients: 8 on radiographs and 7 with CT or gadolinium-enhanced MRI. At surgery, 23 of the 29 (79%) patients had torn labra and femoral head changes. There were an average of 35 loose bodies per patient. Twenty-five of the 29 (86%) had acetabular chondral findings. Five of the 29 patients (17%) eventually underwent total hip reconstruction surgery at a mean of 52 months; 5 of these patients had grade III/IV lesions at the time of arthroscopy. Eleven of the 23 patients (48%) had good to excellent outcomes at an average of 60 months. Recurrent symptoms were seen in 7 patients, and revision arthroscopy was done for 1 patient at 1-year follow-up, 2 patients at 4 years, 1 at 5 years, and 1 at 7-year follow-up. Complications included transient perineal and pedal paresthesia in 2 patients.

CONCLUSION

Patients with synovial chondromatosis with hip central compartment loose bodies that were less than 10 mm benefited from hip arthroscopy. Imaging studies alone failed to establish the diagnosis in 14 of 29 patients (48%). Diagnosis was made by direct visualization via arthroscopy. For patients with grade I/II cartilage change, early diagnosis and treatment via arthroscopy helped. It is a valid and effective treatment at early to intermediate follow-up.

Career plans of current orthopaedic residents with a focus on sex-based and generational differences

BACKGROUND

An orthopaedic workforce shortage has been projected. The purpose of this study is to analyze the supply side of this shortage by ascertaining the career plans of current orthopaedic residents, comparing these plans with the career patterns of practicing orthopaedists, and identifying career-plan differences according to sex.

METHODS

An online, self-administered survey was e-mailed to U.S. orthopaedic residents in postgraduate year three or higher, querying them about their fellowship specialty choice and their career plans.

RESULTS

A total of 498 residents completed the online survey; 430 respondents (86%) were male, sixty-three (13%) were female, and five (1%) did not provide information regarding sex. Ninety-one percent of the residents were planning to enroll in a fellowship, with some respondents indicating more than one subspecialty choice: 28% intended to choose sports; 21%, arthroplasty; 14%, hand surgery, 12%, trauma; 8%, pediatrics; 8%, shoulder and elbow surgery; 8%, spine surgery; 6%, foot and ankle surgery; and 2%, oncology. With regard to the top career priorities of residents in selecting a fellowship specialty, 40% indicated intellectual priorities; 36%, educational; 21%, lifestyle; and 4%, economic. Significantly more women than men were planning on pursuing a pediatric fellowship (24% versus 6%, respectively, p < 0.05) and significantly fewer were planning on pursuing a sports fellowship (11% versus 31%, respectively, p < 0.05). Significantly more women than men planned on a subspecialty-only practice (62% versus 34%, respectively, p < 0.05). The projected retirement age of sixty-four years for current residents is roughly equal to that of the previous generation. There was no difference between men and women with regard to leadership and research aspirations, projected retirement age, and projected workdays per week. However, significantly more women than men (65% versus 47%, respectively) planned on reducing their work hours or changing to part-time status at some time during their careers. There is a higher percentage of female residents (13%) than female practicing orthopaedists (4%) in the United States.

CONCLUSIONS

We should continue efforts to collect workforce data and be proactive to avert or minimize the effect of impending orthopaedic workforce shortages on our patients. Given the trend toward an increasing proportion of female orthopaedists and the higher likelihood that they will reduce their work hours during portions of their career, policymakers should consider training more orthopaedists to ensure patient access to timely, quality orthopaedic care.

What factors influence long-term survivorship after hip arthroscopy?

BACKGROUND

Hip arthroscopy is an evolving procedure. One small study suggested that a low modified Harris hip score and arthritis at the time of surgery were predictors of poor prognosis.

QUESTIONS/PURPOSES

We therefore intended to confirm those findings with a large patient cohort to (1) determine the long-term nonarthritic hip score; (2) determine survivorship; (3) identify risk factors that increase the likelihood of THA; and (4) use those factors to create a usable risk assessment algorithm.

PATIENTS AND METHODS

We retrospectively reviewed 324 patients (340 hips) who underwent arthroscopy for pain and/or catching. Of these, 106 patients (111 hips or 33%) had a minimum followup of 10 years (mean, 13 years; range, 10-20 years). The average age was 39 years (± 13) with 47 men and 59 women. We recorded patient age, gender, acetabular and femoral Outerbridge grade at surgery, and the presence of a labral tear. Followup consisted of a nonarthritic hip score or the date of a subsequent THA. We determined survivorship with the end point of THA for the acetabular and femoral Outerbridge grades.

RESULTS

Overall survivorship among the 111 hips was 63% at 10 years. The average nonarthritic hip score for non-THA patients was 87.3 (± 12.1). Survivorship was greater for acetabular and femoral Outerbridge grades normal through II. Age at arthroscopy and Outerbridge grades independently predicted eventual THA. Gender and the presence of a labral tear did not influence long-term survivorship.

CONCLUSIONS

The long-term survivorship of labral tears with low-grade cartilage damage indicates hip arthroscopy is reasonable for treating labral tears.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Tensile strain in the anterior part of the acetabular labrum during provocative maneuvering of the normal hip

BACKGROUND

Injury of the acetabular labrum is a well recognized cause of hip pain in the young, active patient. The exact mechanism of these injuries remains a subject of speculation, although femoroacetabular impingement and twisting maneuvers have both been proposed as critical factors. We examined the hypothesis that torsional maneuvers of the morphologically normal hip joint generate mechanical strain within the acetabular labrum, particularly in areas that are prone to injury.

METHODS

Seven human cadaver specimens were loaded during five separate maneuvers with external rotation or abduction torques applied to the hip in neutral alignment and in moderate flexion or extension. Tensile strain within the acetabular labrum was measured with use of the technique of roentgen stereophotogrammetric analysis.

RESULTS

Substantial tensile strains were generated within the labrum during each of the loading maneuvers, with no significant difference in strain being noted between the maneuvers. Maximum strain in the anterior part of the labrum averaged 13.6% +/- 7.8% in the axial direction and 8.4% +/- 3.0% in the circumferential direction. The highest mean and maximum strain values were found at the two o'clock position of the labrum, with the highest strain concentration at the bone-labrum interface.

CONCLUSIONS

External rotation and abduction maneuvers of the morphologically normal human hip joint in moderate flexion or extension can generate substantial tensile strains in the anterior part of the acetabular labrum. This finding supports the hypothesis that injury to the anterior part of the labrum may occur from recurrent twisting or pivoting maneuvers of the hip joint in moderate flexion or extension without femoroacetabular impingement.

A proximally coated beaded stem minimum 5-year follow-up

This study reports the minimum 5-year clinical and radiographic outcome of a proximally beaded stem. A consecutive series of 159 primary uncemented total hip arthroplasties in 153 patients were evaluated clinically and radiographically by prospectively determined criteria. Radiographic results showed 97% of the femoral stems are bone ingrown and stable by Engh criteria. There have been 5 femoral revisions (2 for subsidence, 2 for loosening, and 1 broken trunion). At minimum 5-year follow-up, this femoral stem has demonstrated reliable clinical function, bone ingrowth, and proximal bone preservation.

The 2007 Frank Stinchfield Award. The biomechanics of the hip labrum and the stability of the hip

We explored the mechanical factors leading to the formation of labral tears and the effect of these lesions on hip kinematics at the extremes of joint motion. Using a 3D motion analysis system, the stability of six cadaveric hips was measured during loading maneuvers known to impose anterior loads on the joint margin. These measurements were repeated following venting of the capsule, and after creation of a 15-mm tear in the intact labrum. Compared to the intact hip, 43% and 60% less force was required to distract the femur by 3 mm after venting and creation of a tear. An ER torque of 177 in-lbf in 30 degrees of flexion caused the vented and torn specimens to rotate 1.5 degrees +/- 2.7 degrees and 7.1 degrees +/- 4.7 degrees more than the intact specimen, and the femoral head to displace 1.21 +/- 0.53 mm and 0.67 +/- 0.35 mm, respectively. A breach of the integrity of labral function is shown to lead to decreased femoral stability relative to the acetabulum during extreme ranges of motion.

Complex revision total hip arthroplasty with modular stems at a mean of 14 years

We retrospectively reviewed 87 patients (92 hips) who had revision hip surgery to determine whether a proximally coated, modular femoral component would remain stably fixed at long-term followup. Thirteen patients died and 12 patients were lost to followup leaving 62 patients (67 hips) available for review with minimum followup of 8 years (mean, 14 years; range, 8-17 years). Preoperative radiographs were reviewed using Paprosky's classification. Postoperative radiographs were reviewed for osteolysis, endosteal hypertrophy, cortical hypertrophy, distal pedestals, component breakage, and loosening. Thirty-seven hips underwent femoral allografting, 10 of which were proximal femurs. With revision as the endpoint the Kaplan-Meier survivorship (including deaths and loss to followup) was 60% at 14 years. Forty-seven of the 57 (82%) noncemented stems were bone ingrown. All had relative proximal bone preservation and 33 of 57 (58%) had bone hypertrophy in the diaphysis around zones 2 and 6. There were five aseptic failures (9%). Each of those was Paprosky Class IIIB or IV preoperatively. There were no long-term failures in Paprosky Class II or IIIA. The aseptic failures have been re-revised. This modular stem resulted in reliable fixation with relative preservation of proximal bone stock at this intermediate interval in complex revisions in Paprosky Class II and IIIA. Paprosky Class IIIB and IV defects may need additional component fixation options.

Workforce analysis in orthopaedic surgery: how can we improve the accuracy of our predictions?

Since the 1970s, workforce analysis for orthopaedic surgery has predicted a surplus of physicians into the 21st century. In 1998, the RAND study predicted a surplus of 4,100 orthopaedists in 2010. As we approach 2010, we find no surplus. The projected population growth during the next 20 years of those older than age 65 years presupposes a greater need for orthopaedists, given an increase in degenerative disease and fragility fractures associated with aging. The federal government predicts an overall shortage of physicians by 2020. Given the current nature of workforce analysis models and the concerns evoked by these disparate predictions, we, the authors, advocate change. Rather than large studies separated by decades, we recommend routine monitoring of the orthopaedic workforce. Further, we suggest that national, regional, and local organizations, as well as subspecialty societies, work together to monitor current and future orthopaedic workforce needs. Orthopaedic organizations should develop collaborative relationships with experts in the field and devise a true working model that allows for ongoing strategic planning.

Osteonecrosis of the knee after laser or radiofrequency-assisted arthroscopy: treatment with minimally invasive knee arthroplasty

BACKGROUND

Osteonecrosis of the knee after various arthroscopic procedures associated with the use of laser or radiofrequency devices has been described in a few case reports. The purpose of this study was to report on a series of nineteen patients with osteonecrosis of the knee after arthroscopic procedures. A literature search was done to compare this series of patients to previously reported cases. In addition, we analyzed the outcome after treatment with minimally invasive knee arthroplasty.

METHODS

We studied patients who had development of osteonecrosis of the knee after a routine arthroscopic procedure. Preoperative and postoperative clinical notes, radiographs, and magnetic resonance images of patients were analyzed. Only those patients with no evidence of osteonecrosis on preoperative magnetic resonance imaging who later had development of osteonecrosis and subsequently required a knee arthroplasty were included. We conducted a search of the current literature to compare the results seen in our patient population with those seen in other patients with this entity. Patients were followed both clinically and radiographically for a mean of sixty-two months.

RESULTS

A total of nineteen patients met the inclusion criteria. There were fourteen women and five men with a mean age of sixty-nine years. Six patients underwent an arthroscopy with associated holmium or yttrium-aluminum-garnet laser treatment, ten patients had associated radiofrequency treatment, and three patients had microfracture surgery. Subsequent arthroplasty procedures included four unicompartmental knee arthroplasties and fifteen tricompartmental knee arthroplasties. At the time of final follow-up, the mean Knee Society objective score was 95 points.

CONCLUSIONS

Arthroscopic procedures may play a role in the development of osteonecrosis of the knee. To our knowledge, this is the largest series of patients to have development of this condition after arthroscopy with associated laser, radiofrequency, or microfracture surgery. The midterm results of knee arthroplasty in this unique patient population are comparable with those of patients undergoing knee arthroplasty for osteoarthritis of the knee.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Hip arthroscopy: indications, outcomes, and complications

Hip arthroscopy is technically demanding, with a steep learning curve, and requires special distraction tools and operating equipment. Access to the hip joint is difficult because of the resistance to distraction resulting from the large muscular envelope, the strength of the iliofemoral ligament, and the negative intra-articular pressure. This operation should not be done without specific education in its methods.

Constrained acetabular components in complex revision total hip arthroplasty

We retrospectively reviewed 39 consecutive hips in 38 patients to examine the outcome of acetabular fixation and stability in patients with the tripolar constrained acetabular component who had complex revision surgery at 2 to 5 years of followup. Preoperative indications included recurrent dislocation, loose acetabular component with instability, migrated bipolar, resection arthroplasty conversions, and primary arthroplasty. Postoperative radiographs were reviewed for radiolucencies, loosening, migration, or breakage. The patients' average age was 65 years (range, 44-83 years). Thirty-five of the 39 acetabular components (91%) are well fixed and bony ingrown. There were no dislocations. One patient was involved in an motor vehicle accident 1 year postoperatively and sustained a fracture of the ilium and a 2 mm radiolucency about the component which is now stable. Three patients had acetabular revisions. Two patients were revised to a tripolar cemented into a cage and are doing well. The tripolar constrained acetabular component offers reliable fixation and joint stability in patients at high risk for dislocation in this short term followup.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series). See the Guidelines for Authors for s complete description of levels of evidence.

Hip arthroscopy: indications and technical pearls

Our purpose is to describe the evolving indications, technical pearls and contraindications for hip arthroscopy. Although traditional clinical and radiographic measures may identify structural abnormalities or fracture or the hip, recently developed arthroscopic access to the joint has provided new ways of viewing lesions of the labrum, chondral surfaces, and synovium that previously were unrecognized. Development of hip-specific distraction equipment and instruments has allowed treatment of many conditions, especially loose bodies and labral and chondral injuries. In the senior author's experience of more than 2000 hip arthroscopies, several key issues have been resolved. The procedure can be done safely and reproducibly. It can be done with minimal morbidity, and it can be accomplished in a cost-efficient manner as outpatient surgery. Symptom relief and functional improvement can be achieved. Further research is necessary to determine long-term outcomes.

LEVEL OF EVIDENCE

Level V (expert opinion). See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic intervention in early hip disease

Advancement in diagnostic and therapeutic applications for hip arthroscopy have dispelled previous myths about early hip disease. Arthroscopic findings have established the following facts: Acetabular labral tears do occur; acetabular chondral lesions do exist; tears are most frequently anterior and often associated with sudden twisting or pivoting motions; and labral tears often occur in association with articular cartilage lesions of the adjacent acetabulum or femoral head, and if present for years, contribute to the progression of delamination process of the chondral cartilage. Magnetic resonance arthrography represents an improvement over conventional magnetic resonance imaging, it does have limitations when compared with direct observation. Although indications for hip arthroscopy are constantly expanding, the most common indications include: labral tears, loose bodies, chondral flap lesions of the acetabular or femoral head, synovial chondromatosis, foreign body removal, and crystalline hip arthropathy (gout, pseudogout, and others). Contraindications include conditions that limit the potential for hip distraction such as joint ankylosis, dense heterotopic bone formation, considerable protrusio, or morbid obesity. Complication rates have been reported between 0.5 and 5%, most often related to distraction and include sciatic or femoral nerve palsy, avascular necrosis, and compartment syndrome. Transient peroneal or pudendal nerve effects and chondral scuffing have been associated with difficult or prolonged distraction. Meticulous consideration to patient positioning, distraction time and portal placement are essential. Judicious patient selection and diagnostic expertise are critical to successful outcomes. Candidates for hip arthroscopy should include only those patients with mechanical symptoms (catching, locking, or buckling) that have failed to respond to conservative therapy. The extent of articular cartilage involvement has the most direct relationship to surgical outcomes. Improvements in technique and instrumentation have made hip arthroscopy an efficacious way to diagnose and treat a variety of intra-articular problems.

The diagnosis and treatment of labral and chondral injuries

Hip arthroscopy is an excellent way to evaluate, diagnose, and treat acetabular labral and chondral lesions. It is minimally invasive and can be done on an outpatient basis. Candidates for hip arthroscopy will have functionally limiting symptoms and reproducible physical findings. Patients will often have mechanical symptoms such as clicking, catching, locking, or giving way. Symptoms may be preceded by a traumatic event such as a fall or twisting injury or may have an insidious onset. Radiographic studies are not sensitive enough to diagnose intra-articular hip pathology; however, contrast agents used in conjunction with CT and MRI may aid in the diagnosis. Therefore, a high level of clinical suspicion and prudent clinical judgment are warranted. A thorough knowledge of positioning and anatomic relationships to portal placement is necessary to prevent potential neurovascular complications from occurring during hip arthroscopy. Labral tears are the most common cause of mechanical hip symptoms. Tears occur anteriorly, and associated chondral lesions are common. The severity of the chondral lesion is highly correlated with the surgical outcome. The most frequently observed chondral lesion is the watershed lesion, which consists of a labral tear with separation of the labrum from the articular surface at the labral-cartilage junction. The difficulty in identifying these lesions as well as their effect on outcome provides a convincing rationale for arthroscopic hip surgery. Arthroscopic treatment of these tears involves judicious debridement back to a stable base while carefully preserving the capsular labral tissue. Eliminating the source of mechanical symptoms secondary to labral pathology should alleviate the patient's discomfort. Chondral defects are drilled or treated with a microfracture technique to enhance fibrocartilage formation. Patient outcomes are directly dependent on the stage or extent of the labral and chondral lesion.

Hip arthroscopy: when it is and when it is not indicated

Problems that occur in the hip joint, such as a loose body or labral tear, can be treated arthroscopically or with conventional arthrotomy. Hip arthroscopy can facilitate both comprehensive access to and treatment of an evolving series of conditions that affect the hip joint. Candidates for hip arthroscopy should have reproducible symptoms and physical findings that limit function, and a history of mechanical symptoms. Following total hip replacement, when unexplained symptoms persist despite appropriate conservative treatment combined with a negative workup, arthroscopy can be valuable. Intra-articular third bodies often can be successfully removed arthroscopically. Arthroscopy can be valuable after trauma for evacuation of hematomas and removal of chondral loose bodies, and repair of labral injuries. Contraindications to arthroscopy include advanced osteoarthritis, osteonecrosis with femoral head collapse, an ankylosed joint, significant protrusio or grade III or IV heterotopic bone.

The nonarthritic hip score: reliable and validated

The purpose of the current study was to assess the validity, internal consistency, and reproducibility of a short, self-administered hip score designed for use in younger patients with higher demands and expectations than older patients with degenerative joint disease. Validity and internal consistency was studied with 48 consecutive patients with a mean age of 33 years with intractable hip pain and normal plain radiographs. Reproducibility was assessed from data on an additional random sample of 17 patients with hip pain. The Pearson correlation coefficients were 0.82 and 0.59 between the nonarthritic hip score and the Harris hip score and Short Form-12, respectively showing validity. Cronbach's coefficient alpha measuring the internal consistency within each of the score's four domains ranged from 0.69 to 0.92. The test and retest reproducibility ranged from 0.87 to 0.95 for the four subsets and was 0.96 overall. This short, self-administered questionnaire regarding hip pain in young patients with increased activity demands and high treatment expectations is valid compared with previous measures of hip performance, is internally consistent, and is reproducible.

Hip arthroscopy: surgical approach, positioning, and distraction

The hip is the most deeply recessed joint in the body making it difficult to access arthroscopically. However, for the patient with a symptomatic loose body or labral tear open techniques are less advantageous. It is for this reason that, however difficult, minimally-invasive approaches to the hip have been developed. Meticulous attention to proper positioning and portal placement is paramount for safe and successful arthroscopy of the hip. The current authors will review the seminal features of positioning and minimally-invasive surgical approaches to the hip.

Acetabular dysplasia: a paradigm of arthroscopic examination of chondral injuries

The current authors show the value of arthroscopy in diagnosing labral and acetabular cartilage injury and examining the relationship between those injuries and acetabular dysplasia. Between 1989 and 2000, 170 hips in 163 patients with mild acetabular dysplasia or moderate dysplasia with joint preservation had arthroscopic evaluation. Surgical findings were classified by location and by severity of the chondral lesions of the femoral head, acetabulum, and labrum. Of the 170 hips with dysplasia, 122 had labral tears (72%) at the free-margin articular surface and 113 had anterior tears (66%). One hundred hips (59%) had anterior acetabular chondral lesions. Among the 113 patients who had anterior labral tears, 78 hips (69%) had anterior acetabular chondral defects, and 44 hips (39%) had anterior femoral head chondral lesions. Mild uncovering of the anterior femoral head subjects the labrum to increased load and potential susceptibility to tearing most frequently anteriorly. Labral tears may contribute to or can occur in association with articular cartilage lesions of the contiguous femoral head or acetabulum. The mechanism of injury is most likely hyperextension or torque of the hip or both. The findings in the current study support the concept that labral disruption frequently is a predecessor in the continuum of degenerative joint disease.

The Otto E. Aufranc Award: The role of labral lesions to development of early degenerative hip disease

The current authors examined the hypothesis that labral lesions contribute to early degenerative hip disease. Between 1993 and 1999, 436 consecutive hip arthroscopies were done by the senior author. In addition, 54 acetabula were harvested from human adult cadavers. Two hundred forty-one of the 436 (55.3%) patients who had arthroscopies had a 261 labral tears, all located at the articular, not capsular margin of the labrum. Stereomicroscopic examination of the 54 acetabula from cadavers revealed 52 labral lesions. Overall, there was no significant difference between the arthroscopic and cadaveric populations in terms of the incidence of labral tears. (Overall, 73% of patients with fraying or a tear of the labrum had chondral change. Arthroscopic and anatomic observations support the concept that labral disruption and degenerative joint disease are frequently part of a continuum of joint disease.

The watershed labral lesion: its relationship to early arthritis of the hip

This study examined the hypothesis that labral lesions contribute to early degenerative hip disease. Between 1993 and 1999, 436 consecutive hip arthroscopies were performed by the senior author (J.C.M.). In addition, 54 acetabula were harvested from human adult cadavers and 10 hips underwent microangiography to determine labral blood supply. Of the 436 arthroscopic patients, 241 (55.3%) had a total of 261 labral tears, all located at the articular, not capsular, margin of the labrum. Stereomicroscopic examination of the 54 cadaver acetabula revealed a total of 52 labral lesions. Overall, there was no significant difference between the arthroscopic and cadaver populations in terms of the incidence of labral tears (P=.315). There was a high association between labral lesions and adjacent acetabular chondral damage. Arthroscopic and anatomic observations support the concept that labral disruption and degenerative joint disease frequently are part of a continuum of joint pathology.

Frequency Stabilization of a Ho:Tm:YLF Laser to Absorption Lines of Carbon Dioxide

A single-frequency Ho:Tm:YLF laser, operating at an eye-safe wavelength of 2 mum, has been developed with tuning characteristics optimized for spectroscopy of absorption features. The laser frequency was stabilized to three different absorption lines of carbon dioxide by a wavelength modulation technique. Long-term frequency drift has been eliminated from the laser, and shorter-term jitter has been reduced to within 13.5 MHz of the absorption line center. This stabilized laser is an ideal injection seed source for a differential absorption lidar system for measurement of atmospheric gases.

The outcome of trochanteric reattachment in revision total hip arthroplasty with a Cable Grip System: mean 6-year follow-up

We have reviewed 251 hips that were revised by the senior authors with subsequent reattachment using the Dall-Miles Cable Grip System. Of these patients, 223 were available for follow-up. A trochanteric slide osteotomy was used for most cases (n = 170), and the remainder had conventional trochanteric osteotomy to facilitate surgical exposure. Follow-up period was 1 to 8 years. Forty-eight percent (n = 108) of the hips had a previous trochanteric osteotomy. Thirteen percent (n = 30) had a prior trochanteric nonunion. Of the 223 hips, 91% (n = 204) of the trochanters remained attached to the trochanteric bed when reapproximated by the cable grip system. The 2 multifilament cables were passed medially through drill holes in the lesser trochanter in 67% (n = 149) of cases. Of the hips, 16% (n = 35) had 2 cables passed through bone lateral to the prosthesis, and 17% (n = 39) had cables passed 1 medial and 1 lateral to the prosthesis. Cable breakage was noted in 10% (n = 23) of cases. Of those 23, 70% (n = 16) were stainless steel. Unraveling of the cable occurred in 18% (n = 41) of cases. There were 19 nonunions (9%). Of the 19 nonunions, 74% (n = 14) were stainless steel. The trochanter was reattached to bone in 9 hips, to cement in 4 hips, and to a proximal femoral allograft in 6 hips (P = .0001). Eight of the 19 hips (42%) had the cables placed lateral to the prosthesis (P = .0002). When bone-to-bone apposition was achieved at surgery, the nonunion rate was 4%. In this difficult group of revision procedures, the Dall-Miles Cable Grip has provided reliable trochanteric fixation. Factors associated with successful trochanteric healing include use of vitallium cables, use of a trochanteric slide osteotomy, cables passed medially through the lesser trochanter, cerclage rather than intramedullary placement, and bone-to-bone apposition.

Custom and modular components in primary total hip replacement

Cementless custom implants attempted to enhance fit and fill of variable hip geometry. Fabrication of custom implants in referenced from a computed tomography scan, thus allowing three dimensional specifications of femoral anatomy. However, the aggregate charge of manufacturing the implant and obtaining the computed tomography scan is prohibitive in today's healthcare climate. Clinical studies have not shown that customized implants incrementally improve clinical success or implant longevity. Modular prostheses allow the surgeon intraoperative versatility, allowing adjustment of leg length, offset, neck length, anteversion, and fixation. This is particularly helpful in developmental dysplasia of the hip and posttraumatic arthritis. Other advantages of modularity include decreased implant inventory and the ability to remove the femoral head at revision surgery to improve exposure or change head size without component removal. Subsequent clinical experience has witnessed significant drawbacks associated with modularity. These include corrosion, especially with mixed metals, fretting, dissociation, implant fracture below the head and neck taper joint, and reduced range of motion. In addition, thin acetabular polyethylene contributes to higher were rates, earlier failure, local or distal debris particles, and osteolysis. Finally, the cost of modular implants is generally higher than a comparable monolithic prosthesis. In primary hip arthroplasty, use of custom or modular implants should be judicious. Modularity beyond the head and neck junction should be reserved for those cases where a comparable monolithic implant would not suffice.

Minimum four-year radiographic and clinical evaluation of results following femoral revision surgery with the S-ROM modular hip system

Thirty-four patients were reviewed following revision modular cementless reconstruction for proximal femoral deficiency. One patient underwent a Girdlestone conversion for sepsis at 3 years postoperatively, leaving 33 patients with an average follow-up of 51 months (range 48 to 62 months). The average age at surgery was 60 years, and there were 17 right and 16 left hips. Patients were assessed clinically using the Merle d'Aubigné and Postel hip rating system. Radiographic assessment was performed on preoperative and postoperative films. Femoral assessment was performed using the Engh fixation stability score, Gruen zonal system for radiolucencies and observing for the presence or absence of osteolysis. The average pain score was 5.4/6 with 88% having slight or no pain. Only one patient (3%) had thigh pain. Radiographically, the average fixation stability score was 21.7 with features of bony ingrowth present in 97%, and one case with features of stable fibrous ingrowth. There was no evidence of osteolysis.

The role of hip arthroscopy in the diagnosis and treatment of hip disease

Injuries to the hip are commonly encountered by orthopedic surgeons and will, for the most part, respond well to conservative therapy. When a patient's hip pain has not responded to the appropriate treatment and radiographic measurements have not shown any specific pathology, arthroscopy of the hip can be a valuable diagnostic and therapeutic procedure. We retrospectively reviewed 94 consecutive patients who experienced refractory hip pain that persisted longer than 6 months (average: 2.1 years) and who had an average follow up of 2.5 years. Statistical analysis was performed using Fisher's Exact Test (P value) and Pearson (r value) correlation coefficient to compare preoperative symptomatology and physical examination findings with intraoperative pathology. Statistically significant results were obtained when comparing preoperative symptoms of a painful hip click and mechanical symptoms of locking with acetabular labral injuries (P = .000, r = .896) and loose bodies (P = .000, r = .896), respectively. Radiologic studies were nondiagnostic in 76% of patients in this series. Hip arthroscopy can be a valuable and viable procedure in the diagnosis and treatment of protracted or progressive hip pain lasting more than 6 months.