Effectiveness and safety of the posterior approach with soft tissue repair for primary total hip arthroplasty: a meta-analysis

Using mesh in capsule anatomical reconstruction to enhance the stability of high-dislocation-risk hip arthroplasty: a randomized controlled trial

BACKGROUND

Dislocation is a common complication after total hip arthroplasty (THA). This study aimed to compare the outcomes of mesh reconstruction versus conventional capsular repair in maintaining capsular integrity and preventing dislocation after THA.

METHODS

This was a prospective, randomized controlled study of consecutive patients. A total of 124 high-dislocation-risk THAs were identified and randomized into two groups, one using mesh reconstruction and the other using the conventional capsular repair method. Perioperative data and radiological data were collected. Patients were followed up regularly. The main indices were the capsular integrity assessed by magnetic resonance imaging (MRI) and hip dislocation rate. The secondary indices included the Harris hip score (HHS), complications, and satisfaction.

RESULTS

A total of 106 patients completed the follow-up and the average follow-up times were 19 ± 3.1 and 18 ± 3.3 months. The operation time of the mesh group was longer than that of the conventional group (P < 0.001). There were minor differences in acetabular anteversion and abduction angle, and the other data showed no differences. MRI results indicated that the success rate of capsular repair was higher in the mesh group (50 hips, 98%) than in the conventional group (37 hips, 67%) (P < 0.001), and the others failed the repair. Three dislocations occurred in the conventional group, while none occurred in the mesh group. The preoperative HHS (30 points) and postoperative HHS (82 points) of the mesh group were similar to those (35 points, 83 points) of the conventional group (P = 0.164, P = 0.328). Satisfaction had no difference (P = 0.532).

CONCLUSIONS

Compared to conventional repair, mesh reconstruction can effectively maintain capsular integrity and decrease dislocation risk after THA without increasing complications.

LEVEL OF EVIDENCE

Therapeutic study, Level IA.

Superior Transverse Atraumatic Reconstruction (STAR) approach provides a better-compared outcome to standard Direct Superior Approach (DSA): a matched, prospective comparative single-surgeon study

INTRODUCTION

The Direct Superior Approach (DSA) is a muscle-sparing hip approach that does not protect the piriformis and the other short external rotators. We present a DSA modification we named STAR (Superior Transverse Atraumatic Reconstruction), which has DSA advantages but always preserves piriformis. Our study compared the early postoperative, radiological, and functional results of patients undergoing primary total hip arthroplasty (THA) through the STAR approach with a matched DSA group performed by a senior surgeon.

METHODS

Each group, DSA, and STAR included 200 elective primary unilateral THAs performed by the surgeon between 2016-2017 and 2020-2021, respectively. Patients were included in both groups using the same inclusion criteria. Both groups were matched for age and sex. The same postoperative pain management, chemoprophylaxis, and physiotherapy protocols were followed in both groups. Two independent orthopaedic surgeons performed the clinical and radiological follow-up.

RESULTS

The STAR group had significantly lower mean incision length (p = 0.042) and hospital stay (p = 0.002) than the DSA group. The mean intraoperative blood loss (p = 0.085) and the need for blood transfusion (p = 0.228) were less for the STAR than the DSA group. The mean postoperative functional scores improvement was significantly higher for the STAR than the DSA group at the end of the first and third postoperative months.

CONCLUSIONS

The STAR approach offers earlier functional improvement, shorter hospital stay and less transfusion need than DSA for patients undergoing primary THA. Both approaches showed a limited complication risk and an outstanding acetabular and femoral access enabling the procedure.

Earlier functional recovery and discharge from hospital for THA patients operated on via direct superior compared to standard posterior approach: a retrospective frequency-matched case-control study

BACKGROUND

The direct superior hip approach (DSA) has been less researched than other approaches in the literature. We retrospectively compared the early postoperative and functional outcomes of patients with hip osteoarthritis undergoing total hip arthroplasty (THA) via DSA with a matched control group using a standard posterior approach (SPA).

METHODS

The DSA group comprised 100 THAs performed via DSA by a senior surgeon between January 2018 and May 2019. Patients with primary osteoarthritis and ASA score ⩽3 who were eligible for surgery were included. The DSA group was compared to a matched cohort of 100 patients operated on with a SPA in the same period by another chief surgeon. Patients were matched for age, sex, and ASA score. All patients received the same postoperative chemoprophylaxis, pain management and physiotherapy. 2 independent attending arthroplasty surgeons assessed the incision length, operative time, blood loss, hospital stay, and complications. VAS, HHS, and HOOS scores were also evaluated for a year postoperatively.

RESULTS

Mean incision length and hospital stay were significantly lower in the DSA group. DSA patients had non-significantly lower intraoperative blood loss, transfusion needs, and postoperative pain than SPA patients. Mean operation time and complication rate did not differ between groups. The DSA group demonstrated significantly greater functional scores than the SPA group at the first postoperative month. No differences in scores were recorded following the third month.

CONCLUSIONS

The DSA approach may provide earlier functional recovery and hospital discharge for THA patients compared with SPA. DSA was equivalent to SPA concerning pain and blood loss, showing minimal complication rates.

The role of the femoral component orientation on dislocations in THA: a systematic review

INTRODUCTION

Dislocation remains a major complication in total hip arthroplasty (THA), in which femoral component orientation is considered a key parameter. New imaging modalities and definitions on femoral component orientation have been introduced, describing orientation in different planes. This study aims to systematically review the relevance of the different orientation parameters on implant stability.

METHODS

A systematic review was performed according to the PRISMA guidelines to identify articles in the PubMed and EMBASE databases that study the relation between any femoral component orientation parameters and implant stability in primary THA.

RESULTS

After screening for inclusion and exclusion criteria and quality assessment, nine articles were included. Definitions to describe the femoral component orientation and methodologies to assess its relevance for implant stability differed greatly, with lack of consensus. Seven retrospective case-control studies reported on the relevance of the transversal plane orientation: Low femoral- or low combined femoral and acetabular anteversion was statistical significantly related with more posterior dislocations, and high femoral- or combined femoral and acetabular anteversion with anterior dislocations in two studies. There were insufficient data on sagittal and coronal component orientation in relation to implant stability.

CONCLUSION

Because of incomparable definitions, limited quality and heterogeneity in methodology of the included studies, there is only weak evidence that the degree of transverse component version is related with implant stability in primary THA. Recommendations about the optimal orientation of the femoral component in all three anatomical planes cannot be provided. Future studies should uniformly define the three-dimensional orientation of the femoral component and systematically describe implant stability.

MRI assessment of piriformis-sparing posterior approach in total hip arthroplasty

INTRODUCTION

In total hip arthroplasty (THA), the posterior approach is the most common throughout the world. Dislocation is one of the main complications incurred, but the risk may be reduced by sparing posterior structures. Thus, piriformis-sparing posterior approaches (PSPA) were described, and satisfactory conservation of the muscle was reported. On the other hand, a recent cadaver study reported occult intrapelvic piriformis lesions in 91% of cases. In the light of this discordance, we performed pre- and postoperative MRI in THA by PSPA: 1) to assess the fatty infiltration of the piriformis induced by the approach, with particular attention to intrapelvic lesions; and 2) to assess fatty infiltration of the other periarticular muscles.

HYPOTHESIS

The piriformis muscle will show little fatty infiltration following PSPA.

MATERIALS AND METHODS

A continuous prospective single-surgeon series of THA by PSPA included 25 patients. MRI was performed preoperatively and at 3 months and 1 year postoperatively. Fatty infiltration was assessed on the Goutallier classification in all periarticular muscles.

RESULTS

Preoperative MRI was lacking in 4 patients, who were excluded from analysis; 21 patients with MRI were thus analyzed. In the piriformis muscle, there was no significant change in fatty infiltration between preoperative and 3-month (p=0.29) or 1-year (p=0.41) MRI. Two of the 21 patients (9.5%) showed grade 3 or 4 fatty infiltration at 1 year, compared to 0/21 (0%) preoperatively; both showed sacral avulsion of the piriformis. Significant differences between preoperative and 1-year MRI were found for the obturator internus and externus, with grade 3 or 4 infiltration at 1 year in 14 cases for the obturator internus (14/21: 66.7%), in 3/21 for the obturator externus (14.3%) and in 6/21 for the quadratus femoris (28.6%), compared to respectively 0/21 (0%), 0/21 (0%) and 3/21 (14.3%) preoperatively. There were no significant differences for any of the other periarticular muscles.

CONCLUSION

PSPA in THA ensured good conservation of the piriformis. There may, however, be rare and irreversible sacral lesions invisible intraoperatively.

LEVEL OF EVIDENCE

IV; prospective case series.

Use of a modular hip dual-mobility articulation in patients with high risk of dislocation: a relatively small-sized acetabulum in Asian patients may limit its use

BACKGROUND

Dual-mobility hip component is widely used in Europe and North America, because it effectively reduces hip dislocation in primary and revision total hip arthroplasties. However, reports were limited on the use of dual-mobility articulation in Asian populations.

PURPOSE

The aim of this retrospective study was to review the use of modular dual-mobility hip articulation in Asian patients with the high risk factor for hip dislocation. We also discussed the potential concern on the use of dual-mobility articulation in Asian patients.

METHODS

From Jan 2018 to June 2019, 17 patients were included in this study. The mean age of the patients was (73.8 ± 9.5) years (range: 57-88 years). The mean size of acetabular cup and modular DM liner were (49.5 ± 3.4) mm (range, 46-58 mm) and (40.7 ± 3.4) mm (range, 38-48 mm), respectively. The mean follow-up period was (15.8 ± 3.9) months (range, 11-24 months). The primary outcome was the rate of hip dislocation. The secondary outcomes included the Harris Hip Score. Differences were considered statistically significant at p < 0.05.

RESULTS

Hip dislocation, loosening, peri-prosthetic fractures, or intra-prosthetic dislocation was not found in the series. The mean preoperative and postoperative Harris Hip Scores were 42.2 ± 17.2 (range, 15-80) and 74.7 ± 13.5 (range, 52-97), respectively, giving a mean improvement of 32.5 ± 17.2 (range, 4-72). The improvement was statistically significant (p < 0.05).

CONCLUSIONS

In Asian patients with high risk of hip dislocation, the use of modular dual-mobility hip component produces promising outcomes without hip dislocation, but the relatively small-sized acetabulum may limit it widespread application in other populations worldwide.

TRIAL REGISTRATION

HKUCTR-2913 .

Transosseous versus transmuscular repair of the posterior soft tissue in primary hip arthroplasty: a meta-analysis

Background

During the posterior approach, it has been shown that a significant reduction in dislocation rate can be achieved with the repair of the posterior soft tissue. However, no consensus exists about the best way to perform this repair. This review aimed to compare the transosseous with transmuscular repair of the posterior soft tissue in total hip arthroplasty (THA).

Methods

We conducted a meta-analysis to identify studies involving transosseous versus transmuscular repair of the posterior soft tissue in THA in electronic databases, including Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, Wanfang database, up to July 2020. Finally, we identified 1417 patients (1481 hips) assessed in seven studies.

Results

Compared with transmuscular repair, transosseous repair resulted in less incidence of dislocation (P = 0.003), less blood loss during operation (P < 0.00001) and lower VAS score within 3 months (P = 0.02). There were no significant differences in terms of trochanteric fracture rate (P = 0.56), Harris hip score at 3 months (P = 0.35) and 6 months (P = 0.89), VAS score within 6 months (P = 0.53), and operation time (P = 0.70) between two groups.

Conclusion

The lower dislocation rate, less blood loss, and lower VAS scores after operation supported transosseous repair's superiority to transmuscular repair. Besides, no additional medical cost and operating time were associated with transosseous repair compared with transmuscular repair. Hence, we recommend that transosseous repair be chosen first by orthopedists when performing reconstruction of the posterior soft tissue in THA via a posterolateral approach. Given the relevant possible biases in our meta-analysis, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.

Direct superior approach with standard instrumentation for total hip arthroplasty: safety and efficacy in a prospective 200-case series

INTRODUCTION

Direct Superior Approach (DSA) is a muscle sparing approach for total hip arthroplasty (THA) implemented using special instrumentation. There is a lack of information in the literature concerning DSA with standard instrumentation.

MATERIALS AND METHODS

238 patients were recruited for primary THA by a single surgeon from January 2016 until May 2017. 209 patients underwent THA through DSA approach with non-offset acetabular reamers and femoral broaches. We evaluated accuracy of implantation, complications and early functional results. Independent orthopaedic surgeons performed the clinical and radiographic assessments.

RESULTS

200 patients were followed for a year. 3 different implants were used. No sciatic nerve palsies, hip dislocations or fractures were recorded. There was one acute deep and superficial wound infection. The mean functional score was significantly improved at all follow-ups (p < 0.001). 97% of stems were inserted into the neutral coronal and 96% in neutral sagittal alignment. All cups fell within a safe zone of inclination and 91% of anteversion. 2 hips demonstrated heterotopic ossification, Brooker class I. Obese patients had no increased risk of complications.

CONCLUSIONS

DSA with standard instrumentation is safe and efficacious for THA. It offers fast recovery and facilitates correct implantation of different implants, can be useful even for hip dysplasia and obese patients with minimal complication rates.

Postero-posterolateral approach in total hip arthroplasty

Introduction

Evolving surgical techniques in total hip arthroplasty (THA) have sought to make the surgical procedures safer. This requires having highly reproducible incision landmarks and simplifying the procedures. The postero-posterolateral approach, a very posterior incision in the hip, meets those requirements. However, this has not helped to reduce the post-operative dislocation rate. The aim of this study was to assess the relevance of combining the postero-posterolateral approach and next-generation dual mobility cups (DMC) in terms of dislocation risk.

Materials and methods

One hundred and fifty-eight THA were performed consecutively using the postero-posterolateral approach on 150 patients, by a single surgeon, over a 49-month period (November 2010 to December 2014). All acetabular implants were impacted.

Results

Average length of the incision was 7 cm (6 to 9 cm). Mean duration of the surgical procedure was 75 minutes (40 to 100). Mean blood loss was estimated at 210 cc (25 to 410 cc). All patients could walk with assistance the day before transferring to a rehabilitation centre. There was one posterior dislocation (0.63%), without recurrence.

Conclusion

The straightforwardness and reproducibility of the anatomical landmarks used for the postero-posterolateral approach, added to the stability of the dual mobility cup, result in a safe combination in the therapeutic THA arsenal.

Risk factors for dislocation after primary total hip replacement: a systematic review and meta-analysis of 125 studies involving approximately five million hip replacements

BACKGROUND

Dislocation following total hip replacement is associated with repeated admissions to hospital and substantial costs to the health system. Factors influencing dislocation following primary total hip replacement are not well understood. We aimed to assess the association of various factors with dislocation risk following primary total hip replacement.

METHODS

We did a systematic review and meta-analysis of longitudinal studies reporting associations of patient-related, surgery-related, implant-related, and hospital-related factors with dislocation risk after primary total hip replacement. We searched MEDLINE, Embase, Web of Science, and the Cochrane Library for all relevant articles published up to March 8, 2019. Summary measures of association were calculated with relative risks (RRs) and 95% CIs. This study is registered on PROSPERO, number CRD42019121378.

FINDINGS

We identified 149 articles based on 125 unique studies with data on 4 633 935 primary total hip replacements and 35 264 dislocations. The incidence of dislocation ranged from 0·12% to 16·13%, with an overall pooled incidence of 2·10% (95% CI 1·83-2·38) over a weighted mean follow-up duration of 6 years. Based on the median year of data collection, a significant decline in dislocation rates was observed from 1971 to 2015. The risk of dislocation did not differ significantly between male versus female patients (RR 0·97; 95% CI 0·88-1·08), was higher in those aged 70 years and older than in those younger than 70 years (1·27; 1·02-1·57), and was lower in those from high versus low income groups (0·79; 0·74-0·85). White ethnicity (only when compared with Asian ethnicity), drug use disorder, and social deprivation were significantly associated with increased dislocation risk. The risk of dislocation was higher in patients with body-mass index (BMI) of 30 kg/m2 or higher than in those with BMI lower than 30 kg/m2 (RR 1·38; 95% CI 1·03-1·85). Medical factors and those related to surgical history that were significantly associated with increased dislocation risk included neurological disorder, psychiatric disease, comorbidity indices, previous surgery including spinal fusion, and surgical indications including avascular necrosis, rheumatoid arthritis, inflammatory arthritis, and osteonecrosis. Surgical factors such as the anterolateral, direct anterior, or lateral approach, and posterior approach with short external rotator and capsule repair were significantly associated with reduced dislocation risk. At the implant level, larger femoral head diameters, elevated acetabular liners, dual mobility cups, cemented fixations, and standard femoral neck lengths significantly reduced the risk of dislocation. Hospital-related factors such as experienced surgeons and high surgeon procedure volume significantly reduced the risk of dislocation.

INTERPRETATION

Dislocation following primary total hip replacement has declined over time. Surgical approaches that reduce dislocation risk can be used by clinicians during primary total hip replacement, and alternative bearings such as dual mobility can be used in individuals at high risk of dislocation. Modifiable risk factors such as high BMI and comorbidities might also be amenable to optimisation before surgery.

FUNDING

National Institute for Health Research.

Comparison of Two Posterior Soft Tissue Repair Techniques to Prevent Dislocation after Total Hip Arthroplasty via the Posterolateral Approach

BACKGROUND

Although the posterolateral approach is considered to carry a higher early dislocation rate after total hip arthroplasty, posterior soft tissue repair techniques make up for this limitation. Through-bone and through-tendon repair techniques are the two most commonly used techniques. This study aimed to comprehensively compare these techniques and give more evidence-based references for orthopedists. Methods: This retrospective study enrolled 87 patients who underwent posterior soft tissue repair with total hip arthroplasty via the posterolateral approach. The posterior capsular and external rotators were reconstructed to the greater trochanter through drill holes (through-bone, n = 46) or gluteus medius tendon (through-tendon, n = 41). Early dislocation rate, repair-related complications, postoperative pain (visual analog scale, VAS), hip joint function (Harris Hip Scale, HHS), patient satisfaction, and operation-related indexes were evaluated. Results: The discrepancy in early dislocation between the two cohorts was not statistically significant. Operation-related indexes were not significantly different between the two cohorts, except for the postoperative drainage volume (229.46 mL vs. 172.07 mL, p=.013). No patient sustained greater trochanteric fracture and sciatic nerve injury. Each group achieved significant improvements in HHS and VAS scores compared with preoperative values. No statistically significant discrepancy was found in HHS scores between the two groups at the same period, while VAS scores were significantly lower in the through-bone group at 1 week (4.93 vs. 5.68, p=.026) and 1 month (1.72 vs. 1.99, p=.038) after surgery. Higher patient satisfaction was observed in the through-bone group. Conclusions: Although no statistical discrepancy in the early dislocation rate between through-bone and through-tendon repair techniques was observed, lower pain scores and higher patient satisfaction supported the former. We recommend that through-bone repair technique should be chosen first by orthopedists when performing reconstruction of the posterior soft tissue in total hip arthroplasty via a posterolateral approach.

Early dislocation in primary total hip arthroplasty using a posterior approach with repair of capsule and external rotators

OBJECTIVE

To determine the incidence of dislocation after primary total hip arthroplasty using a posterior approach with repair of capsule and transosseous external rotators.

MATERIAL AND METHOD

Historical cohort study between January 2009 and December 2015 of all the cases of dislocation of primary total hip arthroplasty operated using a posterior approach with repair of capsule and transosseous external rotators. Demographic and clinical data concerning the patient, surgery and dislocation were collected and analyzed. A descriptive analysis and a study of survival and risk function were performed by Kaplan Meier's method considering the appearance of a hip dislocation as the final event.

RESULTS

The incidence of dislocation in our study was 1.2% (23 patients). In our study, the highest probability of dislocation occurred in the first 120 days. Forty-three point 5percent of the dislocated patients needed revision surgery.

CONCLUSIONS

Capsular repair and transosseous reattachment of the external rotators can help to reduce the incidence of dislocation in patients undergoing primary total hip arthroplasty through a posterior approach.

Internal Validation of a Predictive Model for Complications After Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty (THA) is projected to increase in prevalence and associated complications will impose significant cost on the US healthcare system. The purpose of this study is to validate a predictive model for postoperative complications utilizing a novel 11-component hip-specific questionnaire encompassing preoperatively available clinical and radiographic data.

METHODS

Consecutive primary THA patients between January 2014 and January 2016 were included. Exclusion criteria included patients without questionnaire scoring variables and less than 1-year follow-up. Patients were stratified into 4 tiers based on their questionnaire score: low risk (>74), mild risk (57-73), moderate risk (41-56), and high risk (<40). A binary logistic regression was performed to determine if the questionnaire predicted complications. Receiver-operator curves were constructed to determine the threshold score below which there was a high likelihood of experiencing a complication.

RESULTS

Four hundred fifty patients were included in the final analysis with a mean (range) follow-up of 2.1 years (1.0-5.9), age of 63.1 years (25.7-9.17), and body mass index of 31.7 kg/m² (17.8-64.5). The complication rate was 13.6%. A hip questionnaire score of 73.8 conferred a 98.5% sensitivity and 98.5% negative predictive value for complications. The questionnaire score was the strongest predictor of a decreased complication likelihood (odds ratio 0.94, 95% confidence interval 0.90-0.97, P < .001). Risk tier was significantly associated with complications (low risk: 0; mild risk: 12; moderate risk: 25; and high risk: 24; P < .001).

CONCLUSION

This novel hip questionnaire demonstrated a high sensitivity and negative predictive value to identify patients at risk for postoperative complications. Future studies should attempt to prospectively validate the use of this questionnaire.

Clinical Considerations for the Use Lower Extremity Arthroplasty in the Elderly

There is an increase in the aging population that has led to a surge of reported cases of osteoarthritis and a greater demand for lower extremity arthroplasty. This article aims to review the current treatment options and expectations when considering lower extremity arthroplasty in the elderly patient with an emphasis on the following subjects: (1) updated clinical guidelines for the management of osteoarthritis in the lower extremity, (2) comorbidities and risk factors in the surgical patient, (3) preoperative evaluation and optimization of the surgical patient, (4) surgical approach and implant selection, and (5) rehabilitation and life after lower extremity arthroplasty.

Comparison of supercapsular percutaneously assisted approach total hip versus conventional posterior approach for total hip arthroplasty: a prospective, randomized controlled trial

BACKGROUND

Total hip arthroplasty (THA) has been one of the most successful orthopedic procedures over the past 30 years. Nowadays, the techniques of exposure for THA have undergone great changes, allowing surgeons to perform THA through mini-incisions. Recently, a novel minimally invasive surgical technique of the supercapsular percutaneously assisted total hip arthroplasty was reported in 2011. The purpose of this study was to compare the SuperPath approach with the conventional posterior approach, in terms early outcomes and radiologic results.

METHODS

Ninety-two consecutive unilateral primary hip osteoarthritis adult patients were randomly divided into two groups. Forty-six patients (SuperPath group) were operated on using the SuperPath approach, and 46 patients (conventional group) were operated on with the conventional posterior approach. Outcomes were evaluated using preoperative index, intraoperative data, and postoperative function data. The positioning of the implants was analyzed by radiography.

RESULTS

No significant difference was detected in skin-to-skin operation time, blood loss, transfusion rate, postoperative complications, abduction angle, anteversion angle, and stem alignments. The incision length and length of stay (LOS) in the SuperPath group were significantly lower. The VAS score in the SuperPath group at the 1-week, 1-month and 3-month postoperative intervals were lower than those VAS scores in the conventional group. The Harris Hip Score and Barthel Index (BI) for Activities of Daily Living in the SuperPath group were significantly higher at the 1- and 3-month follow-up intervals and were not significantly different 1 year after operation.

CONCLUSIONS

This prospective randomized study reveals that the SuperPath technique was associated with shorter LOS, earlier time to walk and climb, and lower postoperative pain levels. It also allowed early postoperative rehabilitation and faster recovery than conventional technique.

Total hip arthroplasty survival in femoral head avascular necrosis versus primary hip osteoarthritis: Case-control study with a mean 10-year follow-up after anatomical cementless metal-on-metal 28-mm replacement

BACKGROUND

Total hip arthroplasty is the most widely used procedure to treat avascular necrosis (AVN) of the femoral head. Few studies have compared the outcomes of THA in femoral head AVN and primary hip osteoarthritis. Therefore we performed a case-control study to compare THA for femoral head AVN vs. primary hip osteoarthritis in terms of: (1) prosthesis survival, (2) complication rates, (3) functional outcomes and radiographic outcomes, (4) and to determine whether specific risk factors for THA failure exist in femoral head AVN.

HYPOTHESIS

THA survival is similar in femoral head AVN and primary hip osteoarthritis.

MATERIAL AND METHODS

We compared two prospective cohorts of patients who underwent THA before 65 years of age, one composed of cases with femoral head AVN and the other of controls with primary hip osteoarthritis. In both cohorts, a cementless metal-on-metal prosthesis with a 28-mm cup and an anatomical stem was used. Exclusion criteria were THA with other types of prosthesis, posttraumatic AVN, and secondary osteoarthritis. With α set at 5%, to obtain 80% power, 246 patients were required in all. Prosthesis survival was assessed based on time to major revision (defined as replacement of at least one implant fixed to bone) and time to aseptic loosening. The other evaluation criteria were complications, Postel-Merle d'Aubigné (PMA) score, and the Engh and Agora Radiographic Assessment (ARA) scores for implant osseointegration.

RESULTS

The study included 282 patients, 149 with AVN and 133 with osteoarthritis. Mean age was 47.8±10.2 years (range, 18.5-65) and mean follow-up was 11.4±2.8 years (range, 4.5-18.3 years). The 10-year survival rates were similar in the two groups: for major revision, AVN group, 92.5% (95% confidence interval [95% CI], 90.2-94.8) and osteoarthritis group, 95.3% (95% CI, 92.9-97.7); for aseptic loosening, AVN group, 98.6% (95% CI, 97.6-98.6) and osteoarthritis, 99.2% (95% CI, 98.4-100). The AVN group had higher numbers of revision for any reason (19 vs. 6, P=0.018) and for dislocation (8 vs. 1, P=0.031). Mean PMA scores at last follow-up were comparable in the AVN group (17.65±1.27 [range, 10-18]) and osteoarthritis group (17.59±1.32 [range, 14-18]) (P=0.139). Osseointegration was also similar in the two groups: global Engh score, 26.51±1.81 (range, 14-27) for AVN and 26.84±0.91 (range, 19.5-27) for osteoarthritis (P=0.065); femoral ARA score, 5.83±0.46 (range, 3-6) for AVN and 5.90±0.42 (range, 3-6) for osteoarthritis (P=0.064); and cup ARA score, 5.74±0.67 (range, 3-6) for AVN and 5.78±0.66 (range, 3-6) for osteoarthritis (P=0.344).

DISCUSSION

Survival in this study was good and consistent with recent data on AVN, with no difference between AVN and osteoarthritis. Revisions for any cause or for dislocation were more common after THA for AVN. Functional outcomes were similar in the AVN and osteoarthritis groups. An anatomical cementless prosthesis combined with metal-on-metal 28-mm bearing provides durable good outcomes.

LEVEL OF EVIDENCE

III, non-randomized comparison of two prospective cohorts.

Fibular nerve palsy after hip replacement: Not only surgeon responsibility. Hereditary neuropathy with liability to pressure palsies (HNPP) a rare cause of nerve liability

Mononeuropathy after surgery may occur and hereditary neuropathy with liability to pressure palsies is a possible pathological condition related to paresis after hip surgery. We present a case of 66-year-old man presenting severe weakness at inferior limb muscles after hip prosthesis revision. Clinic and electrophysiology showed severe right fibular nerve damage and ultrasound found a marked enlargement of the same nerve, associated with focal enlargements in other nerves. A diagnosis of hereditary neuropathy with liability to pressure palsies was suspected and confirmed by genetic test. The patient gradually recovered returning to a normal daily active life. Ultrasound was crucial for diagnosis. The suspicion and diagnosis of latent neuropathy, which can occur after surgical intervention, may lead to a better understand of the risks of the surgery, specific for the patient, and avoid the wrong attribution to surgical malpractice.

Can computer-assisted surgery help restore leg length and offset during THA? A continuous series of 321 cases

INTRODUCTION

Total hip arthroplasty (THA) can bring about complications - particularly leg length differences - that are becoming increasingly litigious. Computer-assisted orthopedic surgery (CAOS) can help optimize the procedure, but its ability to effectively restore leg length is controversial. As a consequence, we carried out a study to determine: (1) its contribution to meeting leg length and offset objectives, (2) its reliability, by evaluating the correlation between radiological and navigation data, (3) its safety, by evaluating navigation-specific and non-specific complications.

HYPOTHESIS

CAOS will help to restore leg length within ± 5 mm in more than 80% of cases.

MATERIAL AND METHODS

A series of 321 continuous cases of cementless THA implanted through the posterolateral approach using CAOS was analyzed retrospectively. With a minimum 1 year follow-up, we evaluated whether the leg length and offset goals were achieved, how well the navigation and radiology data were correlated and whether navigation-specific and non-specific complications occurred. Based on our hypothesis that 80% of patients would have less than 5 mm leg length difference and the null hypothesis (PA = P0) with an alpha of 0.05, 200 observations were required to achieve a power of 90%.

RESULTS

The leg length and offset objectives were achieved in 83.3% and 88% of cases, respectively. Twenty-two patients required a heel wedge to compensate for leg length differences. The correlation between the radiology and surgical navigation data was satisfactory - the Pearson coefficient was 0.79 for length and 0.74 for offset. Intraoperative and postoperative complications or adverse events were found in 14.6% of cases; these were specific to CAOS in 12.1% of cases and non-specific in 2.5% of cases.

CONCLUSION

This study shows the relevance of CAOS for achieving preoperative leg length objectives, with good correlation between navigation and radiology data, and without major complications.

LEVEL OF EVIDENCE

IV - retrospective study.

Comparison of control fasting plasma glucose of exercise-only versus exercise-diet among a pre-diabetic population: a meta-analysis

BACKGROUND/OBJECTIVES

Exercise is considered a protective factor in the prevention of type 2 diabetes, although its role as a sole treatment for pre-diabetes remains unknown. The present meta-analysis compared the effect of exercise-only with exercise-diet interventions on plasma glucose levels among a pre-diabetic population.

SUBJECTS/METHODS

A literature search was conducted using PubMed, EMBASE and Cochrane databases. The Cochrane Collaboration tool was used to assess the quality of each trial. Two reviewers independently performed quality assessment of all included articles. A random effects model was used to calculate the pooled effect.

RESULTS

A total of 4021 participants from 12 studies were included in this meta-analysis, 2045 of them were in the intervention group and 1976 were in the control group. Compared with the exercise-only interventions, the exercise-diet interventions showed a significant effect on decreasing fasting plasma glucose (FPG) levels, with a weighted mean difference (WMD) =-0.22 mmol/l, 95% confidence interval (CI): -0.25, -0.18 (Z=12.06, P<0.05). The subgroup effect of exercise-only interventions did not produce a statistically significant result (WMD=-0.09 mmol/l, 95% CI: -0.18, 0.00, Z=1.91, P>0.05). According to the intervention periods, the pooled effect in the ⩾2-year group was the highest, and its WMD (95% CI) was -0.24 mmol/l (-0.43,-0.05). The pooled effects were statistically significant among the elderly and those of American and European descent, with WMD (95% CI) being -0.19 mmol/l (95% CI: -0.22, -0.15), -0.17 mmol/l (-0.21,-0.12) and -0.22 mmol/l (-0.27, -0.17), respectively.

CONCLUSIONS

Evidence from published trials indicates that exercise-diet interventions showed a significant effect on decreasing FPG levels.