Abductor Muscle Strength Deficit in Patients After Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BackgroundThe aims of this study were to assess and quantify hip abductor muscle strength deficits after total hip arthroplasty (THA) and to determine associations with external factors.MethodsStudies reporting on hip abductor muscle strength before and/or after THA performed for osteoarthritis or atraumatic osteonecrosis of the hip were considered for inclusion. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials. Muscle strength on the affected side was compared with the healthy contralateral side or with control subjects. Study quality was assessed using a modified Newcastle-Ottawa Scale.ResultsNineteen studies reporting on 875 subjects met the inclusion criteria. Patients scheduled for THA had a mean strength deficit of 18.6% (95% confidence interval (CI) [?33.9, ?3.2%]) compared with control subjects. Abductor muscle strength then increased by 20.2% (CI [5.6, 34.8%]) at 4-6 months, 29.6% (CI [4.7, 54.4%]) at 9-12 months, and 49.8% (CI [?31.0, 130.6%]) at 18-24 months postoperatively compared with preoperative values. For unilateral THA, the mean torque ratio was 86.3% (CI [75.4, 97.2%]) and 93.4% (CI [75.1, 111.6%]) before and >24 months after THA, respectively. Study quality was low to moderate.ConclusionHip abductor muscle strength deficits may gradually improve during 24 months after THA possibly without complete recovery. Cautious interpretation of these findings is warranted because high-quality evidence is largely missing.     

Contemporary Ceramic Total Hip Arthroplasty in Patients with Cerebral Palsy: Does It Work?

BackgroundAdult patients with cerebral palsy (CP), who have advanced degenerative arthritis of the hip, have been treated with resection arthroplasty and arthrodesis. Although total hip arthroplasty (THA) has also been used as one of the alternative options, there are few studies on contemporary bearings used in THA. Therefore, we evaluated the results of the contemporary ceramic-on-ceramic THA in adult patients with CP.MethodsFrom January 2005 to December 2007, five adult CP patients (5 hips) underwent THA using contemporary ceramic-on-ceramic bearings. All patients were able to stand or ambulate with intermittent use of assistive devices at home. We retrospectively reviewed the series to determine the results of THA in terms of pain relief, improved function, and durability of prosthesis.ResultsThere were 3 men and 2 women with a mean age of 35.9 years. All patients had pain relief without decline in mobility postoperatively. One hip was dislocated, which was treated successfully with closed reduction and an abduction brace for 2 months. There was no ceramic fracture, loosening, or osteolysis during the mean follow-up of 6.8 years (range, 5.8 to 8.3 years).ConclusionsCementless THA using contemporary ceramic-on-ceramic bearings is a useful option for the treatment of advanced degenerative arthritis of the hip in ambulatory adults with CP.     

Muscular strength after total hip arthroplasty: A prospective comparison of 3 surgical approaches

ResultsDifferences in maximal strength change were greatest after 2 and 8 days. The posterior and anterior approaches produced less decrease in muscular strength than the direct lateral approach. 6 weeks postoperatively, the posterior approach produced greater increase in muscular strength than the direct lateral approach, and resulted in a greater increase in abduction strength than the anterior approach. At 3-month follow-up, no statistically significant differences between the groups were found. The operated legs were 18% weaker in leg press and 15% weaker in abduction than the unoperated legs, and the results were similar between groups.InterpretationThe posterior and anterior approaches appeared to have the least negative effect on abduction and leg press muscular strength in the first postoperative week; the posterior approach had the least negative effect, even up to 6 weeks postoperatively. THA patients have reduced muscle strength in the operated leg (compared to the unoperated leg) 3 months after surgery.Regaining muscular strength is important for postoperative function after hip arthroplasty. Inactivity reduces muscular strength and physical function (McGuire et al. 2001, Suesada et al. 2007, Kortebein et al. 2008), and muscular strength decreases substantially in the first week after total hip arthroplasty (THA) (Holm et al. 2013). Early recovery and rehabilitation of the weakened musculature is therefore of importance (Sicard-Rosenbaum et al. 2002). The type of surgical approach used has a major impact on THA stability and muscle function (Masonis and Bourne 2002).The direct lateral approach (DLA) is associated with a low dislocation risk (Witzleb et al. 2009), but of concern is that it traumatizes the abductor muscles, which can lead to permanent postoperative limp and weakness (Edmunds and Boscainos 2011). The posterior approach (PA) has been associated with postoperative dislocations (Edmunds and Boscainos 2011, Brooks 2013), mainly owing to the small femoral heads used to prevent wear (Bystrom et al. 2003). However, the introduction of highly cross-linked polyethylene into the articulation has reduced wear independently of head diameter (Bragdon et al. 2007), leading to increased use of larger head diameters (Lombardi et al. 2011). It has also been shown that a posterior soft-tissue repair following PA reduces the dislocation rate (van Stralen et al. 2003, Suh et al. 2004). The anterior approach (AA), first described by Robert Judet in 1947 as a modified Smith-Petersen approach, follows the principles of minimally invasive surgery. This approach provides intermuscular and internervous exposure to the hip (Wojciechowski et al. 2007), leading to reduced soft-tissue dissection and trauma (Bergin et al. 2011). Concerns have been related to higher complication rates owing to wound complications, intraoperative fracture, and compromised fixation after minimally invasive surgery, with increased risks of early revision surgery (Graw et al. 2010).There is no consensus on the relative functional advantages of different surgical approaches (Gulati et al. 2008, Edmunds and Boscainos 2011), and differences in maximal strength have not been examined. To our knowledge, there have been no studies comparing the DLA, the PA, and the AA in terms of early maximal muscular strength. We compared these 3 surgical approaches with regard to regaining of maximal muscular strength by 3 months postoperatively in patients undergoing THA.     

Obesity does not influence acetabular component accuracy when using a 3D optical computer navigation system

IntroductionImproper cup positioning and leg length discrepancy (LLD) are two of the most common errors following total hip arthroplasty (THA) and are associated with potentially significant consequences. Obesity is associated with increased risk of mechanical complications, including dislocations, which may be secondary to cup malposition and failure to restore leg length and offset. 3D Optical Camera computerassisted navigation (CAN) system may reduce the risk of component malposition and LLD with real time intraoperative feedback. The aim of this study was to investigate whether the use of CAN influences acetabular component placement (CP) accuracy and leg length restoration in obese (body mass index(BMI)≥35kg/m 2 ) patients undergoing primary THA.MethodsA multi-center retrospective review was conducted identifying consecutive THA cases with BMI > 35kg/m 2 using CAN (Intellijoint Hip, Waterloo, CA) from 2015-2019. These patients were then matched with patients undergoing conventional THA (control) at a 1:1 ratio according to BMI, American Society of Anesthesiologists score, and gender. TraumaCad™ software (Brainlab, Chicago, IL) was used to measure cup anteversion, inclination, and change (Δ) in LLD between pre- and postoperative radiographic images. The safety target zones used as reference for precision analysis of CP were 15°-30° for anteversion and 30°-50° for inclination.Results176 patients were included: 88 CAN and 88 control cases. CAN cases were found to have a lower ΔLLD than controls (3.53±2.12mm vs. 5.00±4.05mm; p=0.003). Additionally, more CAN cases fell within the target safe zone than controls (83% vs.60%, p=0.00083).ConclusionOur findings suggest that the use of a CAN system may be more precise in component placement, and useful in facilitating the successful restoration of preoperative leg length following THA than conventional methodology.     

Early clinical results of total hip arthroplasty assessed with the 25-question Geriatric Locomotive Function Scale and muscle strength testing

Background

We think that it is necessary to evaluate whether the patient after total hip arthroplasty has achieved age-appropriate locomotor ability by improvement in hip joint function. The 25-question Geriatric Locomotive Function Scale (GLFS-25) have been determined age-specific standard values for the general population. The aim of this study was to compare postoperative hip muscle strength and functional performance at 3 months after THA with preoperative levels, and to compare the outcomes at 3 months after THA with the function of age-matched adults without hip disease.

Total hip arthroplasty in an outpatient setting in 27 selected patients

Background and purpose — As a result of introduction of a fast-track program, length of hospital stay after total hip arthroplasty (THA) decreased in our hospital. We therefore wondered whether THA in an outpatient setting would be feasible. We report our experience with THA in an outpatient setting.

Patients and methods — In this prospective cohort study, we included 27 patients who were selected to receive primary THA in an outpatient setting between April and July 2014. Different patient-reported outcome measures (PROMs) were recorded preoperatively and at 6 weeks and 3 months postoperatively. Furthermore, anchor questions on how patients functioned in daily living were scored at 6 weeks and 3 months postoperatively.

Results — 3 of the 27 patients did not go home on the day of surgery because of nausea and/or dizziness. The remaining 24 patients all went home on the day of surgery. PROMs improved substantially in these patients. Moreover, anchor questions on how patients functioned in their daily living indicated that the patients were satisfied with the postoperative results. 1 re-admission occurred at 11 days after surgery because of seroma formation. There were no other complications or reoperations.

Interpretation — At our hospital, with a fast-track protocol, outpatient THA was found to be feasible in selected patients with satisfying results up to 3 months postoperatively, without any outpatient procedure-specific complications or re-admissions.     

Gait Abnormality Predicts Falls in Women After Total Hip Arthroplasty

Background

Patients who undergo total hip arthroplasty (THA) have an increased risk of falls during the first year postoperatively. However, risk factors for falls after THA remain unclear. We investigated the relationship between gait abnormality and falls during the first year after THA.

Quantitative measurements of hip abduction strength in lumbar surgery patients

BackgroundWe sought to evaluate the hip abduction strength in patients before and after lumbar surgery.Materials and methodsEighty-four patients (51 males and 33 females) undergoing surgery for lumbar disc herniation or lumbar canal stenosis were selected. Mean age was 64.7 ± 13.8 years. Seven patients (8.3%) had surgery at multiple levels, including L2-L3 (group A), 27 (32.1%) patients had surgery at multiple levels including L3-L4 (group B), 32 (38.1%) patients had surgery at the L4-L5 level only (group C), and 18 (21.4%) patients had surgery at the L5-S1 level only (group D). Hip abduction strength was measured in the 84 patients preoperatively and in 49 patients postoperatively.ResultsIn all patients, preoperative mean hip abduction strength on the symptomatic side and the asymptomatic side was 71.4 ± 34.5 N and 90.7 ± 36.5 N, respectively (p = 0.0008). In groups A and B, there were no significant differences between the mean hip abduction strength on the symptomatic and contralateral side. In group C, those on the symptomatic and contralateral side were 68.0 ± 33.5 N and 89.3 ± 34.8 N, respectively (p = 0.0181). In group D, those on the symptomatic and contralateral side were 74.3 ± 42.4 N and 101.7 ± 44.7 N, respectively (p = 0.0314). In the 49 patients of all groups that could be measured postoperatively, there were no significant differences between the mean hip abduction strength on both sides.ConclusionsIt was confirmed that the gluteus medius, which was main hip abductor, was mainly innervated by L5 and its mean strength significantly improved postoperatively. The possibility of improvement of hip abduction strength, especially with unchanged tibialis anterior strength, could be very useful for operative decisions.     

Patient-reported outcome after total hip arthroplasty: comparison between lateral and posterior approach

Background and purpose — Criticism of the lateral approach (LA) for hip arthroplasty is mainly based on the risk of poor patient-reported outcomes compared to the posterior approach (PA). However, there have been no controlled studies comparing patient-reported outcomes between them. In this randomized controlled trial, we tested the hypothesis that patient-reported outcomes are better in patients who have undergone total hip arthroplasty (THA) with PA than in those who have undergone THA with LA, 12 months postoperatively.

Patients and methods — 80 patients with hip osteoarthritis (mean age 61 years) were randomized to THA using PA or the modified direct LA. We recorded outcome measures preoperatively and 3, 6, and 12 months postoperatively using the Hip Disability and Osteoarthritis Outcome Score–Physical Function Short Form (HOOS-PS) as the primary outcome. Secondary outcomes were HOOS-Pain, HOOS-Quality-Of-Life, EQ-5D, UCLA Activity Score, and limping.

Results — We found no statistically significant difference in the improvements in HOOS-PS between the treatment groups at 12-month follow-up. All secondary outcomes showed similar results except for limping, where PA patients improved significantly more than LA patients.

Interpretation — Contrary to our hypothesis, patients treated with PA did not improve more than patients treated with LA regarding physical function, pain, physical activity, and quality of life 12 months postoperatively. However, limping was more pronounced in the LA patients.     

The Influence of Obesity on Hip Pain,Function, and Satisfaction 10 Years Following Total Hip Arthroplasty

BackgroundThe prevalence of obesity is rising, and increasing numbers of joint arthroplasty surgeries are being performed on obese patients. Concern exists that obesity increases surgical risk; however, its impact on function following total hip arthroplasty (THA) is inconsistently affirmed and less understood. A paucity exists in the literature pertaining long-term objective functional measures. Therefore, we investigated the impact of obesity on hip pain, function, and satisfaction 10 years following THA.MethodsThis single-center, prospective, observational study categorized consecutive THA patients according to their body mass index to nonobese (<30 kg/m²) and obese (≥30 kg/m²) groups. Preoperative assessment included a numerical pain rating and the Oxford Hip Score. These were repeated along with a 6-minute walk test and a Likert satisfaction scale at 3 months, 1, 5, and 10 years postoperatively.ResultsThe series included 191 primary THA patients. No significant differences were found in hip pain or function between the obese and nonobese groups. Obese patients however had poorer walking capacity (P = .008), were more likely to use walking aids (P = .04), and were less satisfied (P = .04) at 10 years.ConclusionTHA confers significant long-term symptom resolution irrespective of obesity; however, despite undergoing surgery, obese patients can be counseled they may not be as satisfied as or achieve the same walking capacity as nonobese individuals.     

Patient-Reported Outcomes Following Total Hip Arthroplasty: A Multicenter Comparison Based on Surgical Approaches

BackgroundComparisons of patient-reported outcomes (PROs) based on surgical approach for total hip arthroplasty (THA) in the United States are limited to series from single surgeons or institutions. Using prospective data from a large, multicenter study, we compare preoperative to postoperative changes in PROs between posterior, transgluteal, and anterior surgical approaches to THA.MethodsPatient-reported function, global health, and pain were systematically collected preoperatively and at 1, 3, and 6 months postoperatively from patients undergoing primary THA at 26 sites participating in the Comparative Effectiveness of Pulmonary Embolism Prevention After Hip and Knee Replacement (ClinicalTrials.gov: NCT02810704). Outcomes consisted of the brief Hip disability and Osteoarthritis Outcome Score, the Patient-Reported Outcomes Measurement Information System Physical Health score, and the Numeric Pain Rating Scale. Operative approaches were grouped by surgical plane relative to the abductor musculature as being either anterior, transgluteal, or posterior.ResultsBetween 12/12/2016 and 08/31/2019, outcomes from 3018 eligible participants were examined. At 1 month, the transgluteal cohort had a 2.2-point lower improvement in Hip disability and Osteoarthritis Outcomes Score (95% confidence interval, 0.40-4.06; P = .017) and a 1.3-point lower improvement in Patient-Reported Outcomes Measurement Information System Physical Health score (95% confidence interval, 0.48-2.04; P = .002) compared to posterior approaches. There was no significant difference in improvement between anterior and posterior approaches. At 3 and 6 months, no clinically significant differences in PRO improvement were observed between groups.ConclusionPROs 6 months following THA dramatically improved regardless of the plane of surgical approach, suggesting that choice of surgical approach can be left to the discretion of surgeons and patients without fear of differential early outcomes.     

Preoperative methylprednisolone does not reduce loss of knee-extension strength after total knee arthroplasty

Background and purpose — Patients undergoing total knee arthroplasty (TKA) face challenges related to postoperative reduction in knee-extension strength. We evaluated whether inhibition of the inflammatory response by a single preoperative dose of methylprednisolone (MP) reduces the pronounced loss of knee-extension strength at discharge after fast-track TKA.

Patients and methods — 70 patients undergoing elective unilateral TKA were randomized (1:1) to preoperative intravenous (IV) MP 125?mg (group MP) or isotonic saline IV (group C). All procedures were performed under spinal anesthesia without tourniquet, and with a standardized multimodal analgesic regime. The primary outcome was change in knee-extension strength from baseline to 48?hours postoperatively. Secondary outcomes were knee joint circumference, functional performance using the Timed Up and Go (TUG) test, pain during the aforementioned tests, rescue analgesic requirements, and plasma C-reactive protein (CRP) changes.

Results — 61 patients completed the follow-up. The loss in quadriceps muscle strength was similar between groups; group MP 1.04 (0.22–1.91) Nm/kg (–89%) vs. group C 1.02 (0.22–1.57) Nm/kg (–88%). Also between-group differences were similar for knee circumference, TUG test, and pain scores. MP reduced the inflammatory response (CRP) at 24?hours postoperatively; group MP 33 (IQR 21–50) mg/L vs. group C 72 (IQR 58–92) mg/L (p < 0.001), and 48?hours postoperatively; group MP 83 (IQR 56–125) mg/L vs. group C 192 (IQR 147–265) mg/L (p < 0.001), respectively.

Interpretation — Preoperative systemic administration of MP 125?mg did not reduce the pronounced loss of knee-extension strength or other functional outcomes at discharge after fast-track TKA despite a reduced systemic inflammatory response.     

Arthrography for the diagnosis of abductor avulsion after total hip arthroplasty: A comparison of arthrographic and surgical findings in 33 patients

Background?Weakness of the abductor muscles—or even their avulsion—is a potential risk when total hip arthroplasty (THA) is performed using the anterolateral approach. Avulsion of the re-attached gluteus medius leads to a limp, but can also provide an open canal for joint fluid to escape to the trochanteric region. Thus, our hypothesis was that arthrography can be used to diagnose such detachment.

Methods?We compared THA arthrographies with peroperative findings retrospectively in 33 patients who had undergone surgical exploration for a muscle reattachment because of a strong suspicion of abductor avulsion at physical examination.

Results?After a mean follow-up time of 22 (2–57) months after THA, 14/33 patients had a positive (pathological) arthrogram whereas 19 had a negative (normal) result. All 14 patients with a positive arthrogram were verified to have an avulsion of the abductor muscle at the operation. 10 of the 19 patients with a negative arthrogram had an intact abductor insertion, but 9 had an avulsion. All of these 9 patients with the peroperatively disclosed avulsion had a fibrous capsule, which obstructed the fistula leading from the joint cavity to the trochanteric bursa region.

Interpretation?Arthrography is a valuable diagnostic aid in the evaluation of patients with abductor weakness and with Trendelenburg’s gait appearing after a THA performed using the anterolateral approach. A positive finding helps in the operative decision making, but a negative arthrogram is not a reliable predictor.     

Total Hip Arthroplasty Improves Pain and Function but Not Physical Activity

BackgroundPeople with hip osteoarthritis are likely to limit physical activity (PA) engagement due to pain and lack of function. Total hip arthroplasty (THA) reduces pain and improves function, potentially allowing increased PA. PA of THA patients was quantified to 12 months postoperation. The hypothesis was that postoperatively levels of PA would increase.MethodsPA of 30 THA patients (67 ± 7 years) was objectively measured preoperatively and 3 and 12 months postoperation. Harris Hip Score (HHS), Oxford Hip Score (OHS), and 6-minute walk test (6MWT) were recorded. Mixed linear modelling was used to examine relationships of outcomes with time, baseline body mass index (BMI), age, gender, and baseline HHS.ResultsTime was not a significant factor in predicting volume measures of PA, including sit-to-stand transitions, upright time, and steps. Notably, baseline BMI was a significant predictor of upright time, steps, largest number of steps in an upright bout, HHS, and 6MWT. Baseline HHS helped predict longest upright bout, cadence of walking bouts longer than 60 seconds, and OHS. The significant effect of participant as a random intercept in the model for PA outcomes suggested habituation from presurgery to postsurgery.ConclusionVolume measures of PA did not change from presurgery to 12 months postsurgery despite improvement in HHS, OHS, and 6MWT. Baseline BMI was a more important predictor of upright activity and stepping than time. Preoperative and postoperative PA promotion could be used to modify apparently habitual low levels of PA to enable full health benefits of THA to be gained.     

Similar range of motion and function after resurfacing large–head or standard total hip arthroplasty

Background and purpose Large–size hip articulations may improve range of motion (ROM) and function compared to a 28–mm THA, and the low risk of dislocation allows the patients more activity postoperatively. On the other hand, the greater extent of surgery for resurfacing hip arthroplasty (RHA) could impair rehabilitation. We investigated the effect of head size and surgical procedure on postoperative rehabilitation in a randomized clinical trial (RCT).

Methods We followed randomized groups of RHAs, large–head THAs and standard THAs at 2 months, 6 months, 1 and 2 years postoperatively, recording clinical rehabilitation parameters.

Results Large articulations increased the mean total range of motion by 13° during the first 6 postoperative months. The increase was not statistically significant and was transient. The 2–year total ROM (SD) for RHA, standard THA, and large–head THA was 221° (35), 232° (36), and 225° (30) respectively, but the differences were not statistically significant. The 3 groups were similar regarding Harris hip score, UCLA activity score, step rate, and sick leave.

Interpretation Head size had no influence on range of motion. The lack of restriction allowed for large articulations did not improve the clinical and patient–perceived outcomes. The more extensive surgical procedure of RHA did not impair the rehabilitation.

This project is registered at ClinicalTrials.gov under # NCT01113762.     

Prognostic factors affecting clinical outcomes after arthroscopic rotator cuff repair: importance of functional recovery by 3 months after surgery

Background

To examine important factors that affect clinical outcomes following arthroscopic rotator cuff repair (ARCR).

Methods

Among 163 patients who underwent ARCR, we included 71 shoulders in 71 patients whose progress was monitored for >?2?years, postoperatively. We divided the patients into groups A (scores ≥?83 points, 59 patients) and B (scores <?83 points, 12 patients) using the Japanese Orthopedic Association (JOA) score at 24?months. We then conducted univariate and multivariate analyses of pre- and postoperative (2 and 3?months, respectively) factors.

Results

The mean JOA score for all patients significantly improved from 63.7?±?11.5 points preoperatively to 90.3?±?9.6 points at 24?months postoperatively (P?<?0.05). However, there were no significant between-group differences in the preoperative scores. In addition, there were no significant differences in the postoperative re-tear rate. Univariate analysis revealed that the range of motion (preoperative abduction and postoperative elevation, abduction, internal rotation, and external rotation), muscle strength (external rotation 3?months postoperatively), postoperative pain level [visual analog scale (VAS) maximum score, 10 points], partial repair, Cofield classification, and preoperative width were significant factors (P?<?0.05 for all factors). Multivariate and receiver operating characteristic curve analyses showed that VAS at 2?months postoperatively and elevation at 3?months postoperatively were significant factors.

Conclusions

To obtain a JOA score of ≥?83 points at 24?months postoperatively, following ARCR, a postoperative VAS of <?5 points at 2?months and postoperative elevation of ≥?110° at 3?months should be achieved.

     

High failure rate after internal fixation and beneficial outcome after arthroplasty in treatment of displaced femoral neck fractures in patients between 55 and 70 years

Background and purpose — The treatment of patients between 55 and 70 years with displaced intracapsular femoral neck fracture remains controversial. We compared internal fixation (IF), bipolar hemiarthroplasty (HA) and total hip arthroplasty (THA) in terms of mortality, reoperations and patient-reported outcome by using data from the Norwegian Hip Fracture Register.

Patients and methods — We included 2,713 patients treated between 2005 and 2012. 1,111 patients were treated with IF, 1,030 with HA and 572 patients with THA. Major reoperations (defined as re-osteosynthesis, secondary arthroplasty, exchange, or removal of prosthesis components and Girdlestone procedure), patient-reported outcome measures (satisfaction, pain, and health-related quality of life (EQ5D) after 4 and 12 months), 1-year mortality, and change in treatment methods over the study period were investigated.

Results — Major reoperations occurred in 27% after IF, 3.8% after HA and 2.8% after THA. 549 patients (20% of total study population) answered both questionnaires. Compared with IF, patients treated with THA were more satisfied after 4 and 12 months, reported less pain after 4 months and 12 months, had a higher EQ5D-index score after 4 months and 12 months, and EQ-VAS score after 4 months. Compared with IF, patients treated with HA were more satisfied and reported less pain after 4 months. EQ5D-index and EQ-VAS were similar. Patients treated with HA had higher 1-year mortality and had more comorbidities than both the THA and IF group. All these differences were statistically and clinically significant.

Interpretation — This study showed high reoperation rate after IF and better patient-reported outcome after both THA and HA with medium follow-up. Patients selected for HA represented a frailer group than patients treated with THA or IF.     

Contemporary Total Hip and Total Knee Arthroplasty Results in Patients with Hemochromatosis

BackgroundHemochromatosis can result in metabolic bone pathology (due to excessive iron absorption) and degenerative joint disease, leading to total joint arthroplasties. The aim of this study is to analyze the survivorship, complications, radiographic results, and clinical outcomes of patients with hemochromatosis who received either a total hip arthroplasty (THA) or a total knee arthroplasty (TKA).MethodsWe identified 34 lower extremity arthroplasties in 29 patients with hemochromatosis performed between 2000 and 2016. There were 17 primary THAs in 15 patients and 17 primary TKAs in 14 patients. Mean age at arthroplasty was 63 years with 76% being male. The mean body mass index was 28 kg/m². Mean follow-up was 5 years.ResultsThe survivorship free from any revision for THAs was 94% at 10 years. One patient was revised for aseptic loosening of the femoral stem at 6 months. In THA patients, no infections, no other complications, and no radiographic evidence of aseptic loosening were identified. Harris Hip Scores improved from a mean of 55 preoperatively to 94 postoperatively (P < .001). The survivorship free from any revision for TKAs was 100% at 10 years. Two patients (12%) developed acquired idiopathic stiffness postoperatively; no infections were identified. There was no radiographic evidence of aseptic loosening in any TKA. Knee Society Scores improved from a mean of 61 preoperatively to 94 postoperatively (P < .001).ConclusionThis study found excellent survivorship, significant improvements in clinical outcomes, and a very low complication profile for both THA and TKA in patients with hemochromatosis.     

Patient Factors That Matter in Predicting Hip Arthroplasty Outcomes: A Machine-Learning Approach

BackgroundDespite the success of total hip arthroplasty (THA), approximately 10%-15% of patients will be dissatisfied with their outcome. Identifying patients at risk of not achieving meaningful gains postoperatively is critical to pre-surgical counseling and clinical decision support. Machine learning has shown promise in creating predictive models. This study used a machine-learning model to identify patient-specific variables that predict the postoperative functional outcome in THA.MethodsA prospective longitudinal cohort of 160 consecutive patients undergoing total hip replacement for the treatment of degenerative arthritis completed self-reported measures preoperatively and at 3 months postoperatively. Using four types of independent variables (patient demographics, patient-reported health, cognitive appraisal processes and surgical approach), a machine-learning model utilizing Least Absolute Shrinkage Selection Operator (LASSO) was constructed to predict postoperative Hip Disability and Osteoarthritis Outcome Score (HOOS) at 3 months.ResultsThe most predictive independent variables of postoperative HOOS were cognitive appraisal processes. Variables that predicted a worse HOOS consisted of frequent thoughts of work (β = ?0.34), frequent comparison to healthier peers (β = ?0.26), increased body mass index (β = ?0.17), increased medical comorbidities (β = ?0.19), and the anterior surgical approach (β = ?0.15). Variables that predicted a better HOOS consisted of employment at the time of surgery (β = 0.17), and thoughts related to family interaction (β = 0.12), trying not to complain (β = 0.13), and helping others (β = 0.22).ConclusionsThis clinical prediction model in THA revealed that the factors most predictive of outcome were cognitive appraisal processes, demonstrating their importance to outcome-based research.Level of evidencePrognostic Level 1.