Short Rotators Research Articles

A PROSPECTIVE RANDOMIZED CONTROLLED TRIAL COMPARING THE DIRECT SUPERIOR APPROACH WITH THE POSTERIOR APPROACH FOR TOTAL HIP ARTHROPLASTY

The direct superior approach (DSA) is a modification of the posterior approach (PA) that preserves the iliotibial band and short external rotators except for the piriformis or conjoined tendon during total hip arthroplasty (THA). The objective of this study was to compare postoperative pain, early functional rehabilitation, functional outcomes, implant positioning, implant migration, and complications in patients undergoing the DSA versus PA for THA.This study included 80 patients with symptomatic hip arthritis undergoing primary THA. Patients were prospectively randomised to receive either the DSA or PA for THA, surgery was undertaken using identical implant designs in both groups, and all patients received a standardized postoperative rehabilitation programme. Predefined study outcomes were recorded by blinded observers at regular intervals for two-years after THA. Radiosteriometric analysis (RSA) was used to assess implant migration.There were no statistical differences between the DSA and PA in postoperative pain scores (p=0.312), opiate analgesia consumption (p=0.067), and time to hospital discharge (p=0.416). At two years follow-up, both groups had comparable Oxford hip scores (p=0.476); Harris hip scores (p=0.293); Hip disability and osteoarthritis outcome scores (p=0.543); University of California at Los Angeles scores (p=0.609); Western Ontario and McMaster Universities Arthritis Index (p=0.833); and European Quality of Life questionnaire with 5 dimensions scores (p=0.418). Radiographic analysis revealed no difference between the two treatment groups for overall accuracy of acetabular cup positioning (p=0.687) and femoral stem alignment (p=0.564). RSA revealed no difference in femoral component migration (p=0.145) between the groups at two years follow-up.There were no differences between patients undergoing the DSA versus PA for THA with respect to postoperative pain scores, functional rehabilitation, patient-reported outcome measurements, accuracy of implant positioning, and implant migration at two years follow-up. Both treatment groups had excellent outcomes that remained comparable at all follow-up intervals.

The short external rotator muscles of the hip: a cadaveric study on 18 specimens with clinical implications.

The short external rotator muscles (SERMs) of the hip are composed of six postural muscles that constitute a single functional unit that is aligned to coapt the articular surfaces of the hip joint, providing dynamic stability. This study aims to provide a morphometric evaluation of this unit that could benefice clinical practice. In particular, the implication of the morphology and direction of the hip triceps tendon when performing a posterolateral approach for total hip arthroplasty. A total of 18 cadaveric hips were dissected rigorously. Variations of the origin, course and insertion of all SERMs were recorded and quantified. Measurements were conducted for the following parameters: total muscle lengths, intra-muscular and extra-muscular tendon lengths, muscle sagittal and frontal angles, and femoral neck length. Correlation was searched for between total muscle length and femoral neck length. Results were as follows: (a) the obturator internus and externus muscles insert quasi perpendicularly on the proximal femur, (b) both gemelli take distal insertion onto the tendon of the obturator internus to form the hip triceps tendon, (c) morphometric data of the studied parameters was reported, and (d) moderate to high correlation with femoral neck length was found for all muscles but the quadratus femoris. Our results showed that the direction of the hip triceps tendon is always orthogonal to the proximal femur in the frontal plane. Such anatomical reference could be used when performing total hip arthroplasty with the posterolateral approach. Future research is needed to assess whether the easy identification and re-insertion of the hip triceps could reduce leg length discrepancy and offset.

Advances in study of surgical approaches and MRI evaluation of total hip arthroplasty

To review the research on different surgical approaches and MRI evaluation of total hip arthroplasty (THA), to clarify the possible muscle damage caused by different approaches, and to help clinicians avoid intraoperative muscle damage and identify the causes of certain muscle-related complications after operation. The research literature on different surgical approaches and MRI evaluation of THA at home and abroad was extensively reviewed to summarize the MRI performance of the posterior approach, modified direct lateral approach, direct anterior approach, and minimally invasive anterolateral approach (also called Orthopadische Chirurgie Munchen approach). The traditional posterior approach mainly damages the short external rotator muscle group and increases the incidence of postoperative dislocation; the piriformis-keeping posterior approach significantly improves the quality of the pyriformis tendon in the postoperative period, but it may lead to damage to the intrapelvic portion of the piriformis muscle. The modified direct lateral approach mainly damages the gluteus medius muscle, which increases the risk of postoperative claudication. The direct anterior approach mainly damages the vastus tensoris muscle and may result in damage to the short external rotator muscle group and the muscles around the incision. The minimally invasive anterolateral approach primarily damages the superior gluteal nerve, which subsequently leads to denervation of the broad fascial tensor fasciae latae, and this approach may also result in injury to the gluteus medius and gluteus minimus muscles. The muscle damage status significantly affects prognosis, and the minimally invasive approach is more suitable for elderly patients. MRI can clarify the different types of muscle damage caused by different surgical approaches. Minimally invasive approaches can reduce muscle damage and improve postoperative function compared with traditional approaches, and can benefit elderly patients more, but due to the small field, forcing to expand the surgical field will lead to unintended muscle damage and reduce postoperative function.

Two variant muscles in the gluteal region.

The short lateral rotators of the thigh found in the gluteal region can have morphological variations. During anatomical dissection of a right lower limb, two variant structures were found in this region. The first of these accessory muscles originated from the external surface of the ramus of the ischium. Distally, it was fused with the gemellus inferior muscle. The second structure comprised tendinous and muscular parts. The proximal part originated from the external part of the ischiopubic ramus. It inserted on the trochanteric fossa. Both structures were innervated by small branches of the obturator nerve. The blood supply was via branches of the inferior gluteal artery. There was also a connection between the quadratus femoris and the superior part of the adductor magnus. These morphological variants could be clinically important.

Optimal hip capsular release for joint exposure in hip resurfacing via the direct anterior approach.

Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA. Nine fresh-frozen hip joints from five pelvis to mid-tibia cadaveric specimens were approached using the DAA. A custom fixture consisting of a six-axis force/torque sensor and motion sensor was attached to tibial diaphysis to measure manually applied torques and joint angles by the surgeon. Following dislocation, the torques generated to visualize the acetabulum and proximal femur were assessed after sequential release of the joint capsule and short external rotators. Following initial exposure, the ischiofemoral ligament (7 to 8 o'clock) was the largest restrictor of exposure of the acetabulum, contributing to a mean 25% of overall external rotational restraint. The ischiofemoral ligament (10 to 12 o'clock) was the largest restrictor of exposure of the proximal femur, contributing to 25% of overall extension restraint. Releasing the short external rotators had minimal contribution in torque generated during joint exposure (≤ 5%). Adequate exposure of both proximal femur and acetabulum may be achieved with minimal torque by performing a full proximal circumferential capsulotomy while preserving short external rotators. The joint torque generated and exposure achieved is dependent on patient factors; therefore, some cases may necessitate further releases.

Traumatic gluteus maximus femoral insertion tear

With hip fracture dislocation, there is a wide variety of injuries, and one of the least and rarely to be seen is a gluteus maximus femoral insertion tear. We report this case to encourage further sharing of similar cases, establish a treatment protocol, and avoid such potential complications. We present this rare case of a 36-year-old male, a victim of a severe motor vehicle collision, who presented with a head contusion, right gluteus maximus femoral insertion tear, right hip dislocation with closed posterior wall acetabulum fracture, intra-articular incarcerated fragment, and multiple fractures. After the reduction of his hip and splinting of his concomitant fractures and optimization of the general condition, he underwent open reduction internal fixation of the posterior acetabulum wall. Intraoperatively, he found to have a rupture of gluteus maximus and short external rotators for which he had gluteus maximus direct repair to its insertion and partial repair for his severely damaged external rotators. The patient developed a surgical site infection post operation, treated by multiple sessions of irrigation and debridement and culture-based intravenous venous antibiotics for six weeks. At the 7-month outpatient clinical follow-up, the patient function was able to mobilize with a limping gait using a cane and extreme limitation of his abduction, external rotation, and extension due to the development of heterotopic ossification, which could be due to prolonged intensive care unit admission due to head injury or hip external rotators rupture or multiple surgeries that he underwent. This rare finding of gluteus maximus ruptur is the first of a kind in our institute, and such a finding to be considered before treatment of such severe injuries and questioning the need for magnetic resonance imaging for traumatic hip dislocations plus prophylactic treatment of heterotopic ossification to optimize the functional outcome post-operative.

Clinical Outcomes of Bipolar Hemiarthroplasty with a Conjoined Tendon-Preserving Posterior Approach for Femoral Neck Fractures.

Background and Objectives: The conventional posterior approach in the lateral decubitus position is widely used for femoral neck fractures in femoral hemiarthroplasty. Postoperative dislocation is the major problem with this approach. The conjoined tendon-preserving posterior (CPP) approach is a less invasive surgical approach than the conventional posterior approach to the hip, maintains posterior stability, and preserves short external rotators and joint capsules. However, the mention was required to avoid muscle damage and whether muscle damage affects postoperative dislocation or not. The current study aimed to evaluate the clinical results of the CPP approach in hemiarthroplasty for femoral neck fractures and identify muscle damage risk factors. Materials and Methods: This study was a retrospective cohort study and included 170 hips in 168 patients. The mean age at the operation was 81.2 years. The preservation rate of the internal obturator muscle and gemellus inferior muscle and factors related to intraoperative short rotator muscle injury were investigated retrospectively. The postoperative complications and the relation between muscle damage and postoperative dislocation were investigated. Results: In the four hips (2.3%) with the obturator internus muscle damage, thirty-eight hips (22.4%) with gemellus inferior muscle damage were detected; in the muscle-damaged cases, the high body mass index (BMI) was significantly higher. The complication occurred in four hips (2.3%), including postoperative posterior dislocation in one hip without muscle damage (0.6%). Postoperative infection occurred in one hip (0.6%), and peroneal or sciatic nerve paralysis was suspected in two hips (1.1%). Conclusions: Compared to the conventional posterior approach in previous reports, the CPP approach reduces postoperative dislocation. A higher BMI is a risk factor for muscle damage, and the gemellus inferior muscle damage has no effect on postoperative dislocation. The CPP approach for BHA appeared to be an effective treatment method.

Failed nonunion subtrochanteric femur fracture managed with uncemented total hip replacement

Abstract Subtrochanteric fracture is a fracture between the lesser trochanter and 5 cm distal to the lesser trochanter. It accounts approximately for 10%–30% of all hip fractures and affects persons more than 60 years of age. Bimodal distribution has greater incidences in 20–40 years of age and persons more than 60 years of age. Deforming forces on the proximal fragment are abduction by the gluteus medius and minimus, flexion by iliopsoas, and external rotation by short external rotators; whereas, deforming forces on the distal fragment are adduction and varus by adductors. Failure of subtrochanteric fracture treatment is frequently associated with unstable fracture patterns, poor bone quality, or suboptimal position of fixation devices. Such complications following treatment failure may result in nonunion, leading to pain or malunion, severe bone defects, infection, articular cartilage damage, and even post-traumatic arthritis hip, which poses a significant challenge in subsequent surgeries. Therefore, in this particular case, we were left with only two options, such as (1) re-osteosynthesis using limb reconstruction surgeries (LRS) and (2) and prosthetic replacement. We opted for uncemented long stem total hip replacement to get diaphyseal hold as it has many advantages over LRS like a high success rate, a better quality of life, improved early mobility, and life-long lasting results. LRS was not opted as a choice of surgery as it has some disadvantages like pin-tract infection, more maintenance and compliance needed, the frame being bulky and cumbersome, and the risk of fracture at the pinhole site. Moreover, in this particular case, bone grafts from all accessible sites were used from previous surgeries. Uncemented long-stem total hip replacement can serve as an efficient salvage procedure in such cases. Post-operatively on follow-up at 2 months, the patient was able to fully bear weight without support. The range of motion at the right hip joint where the patient was able to do flexion 100ʹ, abduction 50ʹ, and adduction 30ʹ. We were able to correct limb length discrepancy by 5 cm (pre-operative discrepancy was 7 cm). Our achievement shows that uncemented long stem total hip replacement is a beneficial and effective procedure for salvaging the failed treatment of subtrochanteric fractures. Such procedures have shown satisfactory functional outcomes, stable fixation, and survival rates for these complex situations.

Short-Term Complications of Relative Femoral Neck Lengthening Combined with Extra-Articular Osteotomies of the Proximal Femur.

Relative femoral neck lengthening (RNL) is a newer technique to correct coxa breva and coxa vara to relieve a femoro-acetabular impingement and improve hip abductor function without changing the position of the head on the shaft. Proximal femoral osteotomy (PFO) changes the position of the femoral head relative to the shaft. We studied the short-term complications of procedures that combined RNL with PFO. All hips that underwent RNL and PFO using a surgical dislocation and extended retinacular flap development were included. Hips that were treated only with intra-articular femoral osteotomies (IAFO) were excluded. Hips that underwent RNL and PFO, with IAFO and/or acetabular procedures were included. Intra-operative evaluation of the femoral head blood flow was performed with the drill hole technique. Clinical evaluation and hip radiographs were obtained at 1week, 6weeks, 3months, 6months, 12months and 24months. Seventy two patients (31 males, 41 females, 6-52years of age) underwent 79 combined RNL and PFO. 22 hips underwent additional procedures like head reduction osteotomy, femoral neck osteotomy, and acetabular osteotomies. There were 6 major and 5 minor complications noted. Two hips developed non-unions, both with basicervical varus-producing osteotomies. Four hips developed femoral head ischemia. Two of these hips avoided collapse with early intervention. One hip had persistent abductor weakness requiring hardware removal and three hips, all in boys developed symptomatic widening of the hip on the operated side from varus-producing osteotomy. One hip had asymptomatic trochanteric non-union. RNL is routinely performed by releasing the short external rotator muscle tendon insertion from the proximal femur to raise the posterior retinacular flap. Though this technique protects the blood supply from direct injury, it seems to stretch the vessels with major corrections in the proximal femur. We recommend evaluating the blood flow intraoperatively and postoperatively and taking necessary steps early to decrease the stretch on the flap. It may be safer to avoid raising the flap for major extra-articular proximal femur corrections. The results of this study suggest ways to improve the safety of procedures that combine RNL and PFO.

A piriformis-preserving posterior approach reduces dislocation rate of the hemiarthroplasty in patients with femoral neck fracture

IntroductionThe posterior approach (PA) for hemiarthroplasty (HA) in patients with femoral neck fracture (FFN) has a high risk of dislocation; however, by preserving the piriformis muscle, the dislocation rate could be lowered considerably. The aim of this study was to compare the surgical complications of the piriformis-preserving posterior approach (PPPA) and the PA in patients with FNF treated with HA. MethodsOn 1 January 2019, the PPPA was introduced at two hospitals as the new treatment standard. The sample size was calculated based on a 5 percentage point dislocation reduction and 25% censoring; a sample of 264 patients per group was determined. An approximately 2-year inclusion period with 1-year follow-up was estimated, including a historical cohort from 2 years before the PPPA introduction. Data were retrieved from health care records and X-ray images from the hospitals’ administrative databases. Relative risk (RR) and 95% confidence intervals were calculated using Cox regression and adjusted for age, sex, comorbidity, smoking, surgeon experience and implant type. ResultsThere were 527 patients included in the study, of which 72% were women and 43% were above 85 years old. There were no baseline differences between the PPPA and PA groups in sex, age, comorbidity, body mass index, smoking, alcohol, mobility, length of surgery, blood loss or implant positioning, but there were differences in 30-day mortality, surgeon experience and implant type.The dislocation rate reduced from 11.6% in the PA group to 4.7% in the PPPA group (p = 0.004), with an RR of 2.5 (1.2; 5.1). The reoperation rate reduced from 6.8% with the PA to 3.3% with the PPPA (p = 0.022), with an RR of 2.1 (0.9; 5.2), and total surgery-related complications reduced from 14.7% with the PA to 6.9% with the PPPA (p = 0.003), with an RR of 2.4 (1.3; 4.4). InterpretationChanging from PA to PPPA in patients with FNF treated with HA resulted in a more than 50% reduction in dislocation and reoperation rates. This approach was easily introduced and may enable further lowering of dislocation rates through the sparing of all short external rotators.

EFFECTS ON EXTERNAL ROTATOR MUSCLE STRENGTH IN NECK OF FEMUR FRACTURE PATIENTS OPERATED WITH SOUTHERN MOORE APPROACH FOR BIPOLAR HEMIARTHROPLASTY OF HIP

Introduction: Neck of femur fracture is one of the most common fractures of elderly age group. Bipolar Hemiarthroplasty of Hip is most widely accepted treatment protocol. Posterior (Southern moore) approach is one of the widely used approach all over the world. In this approach Short external rotators are detached from their insertion and reattached. Hence there is a need to assess the function of External rotation of Hip post operatively. A Methods: Prospective study was carried out in patients with Neck of femur fracture who underwent Bipolar Hemiarthroplasty of Hip with Southern moore approach from May 2021 to May 2022 in a single institution. All patients were followed up and assessed at 6 weeks, 3 months and 6 months and function of short external rotators was assessed with Augustssons Strength test. Control for the muscle strength was considered opposite (Normal) side of hip. Patients with Any other ipsilateral fractures were excluded. Analysis of the data was done for the external rotator muscle strength at 6 weeks, 3 months and 6 months with comparison to normal hip of patient. The overall mean age was 69 years. Results: All the patient were followed up till 6 months post operatively. There was reduced strength of short external rotators in all the patients compared to normal hip at 6 weeks, with no significant difference in strength at 3 months. 12 out of 13 had equal muscle strength at 6 months. This study concludes that Detaching of Short external rotator in southe Conclusion: rn moore approach does not affect the muscle strength at 6 months. However it is found to be weaker in initial month.

Targeting of Periprosthetic Muscles for the Ultrasonographic Screening of Hip Abnormalities in Hip Resurfacing Arthroplasty Patients.

Hip resurfacing arthroplasty (HRA) patients require subsequent annual screening for postoperative complications. Ultrasonography may be useful for this purpose but lacks a screening protocol for hips. The purpose of this study was to evaluate the accuracy of ultrasonography for detecting postoperative complications in HRA patients using a screening protocol that specifically targets periprosthetic muscles. We enrolled 45 hips from 40 HRA patients with a mean follow-up period of 8.2 years. MRI and ultrasonography scans were simultaneously conducted at follow-up. The ultrasonography assessments were conducted on the anterior part of the hip that targets iliopsoas, sartorius, rectus femoris, lateral with anterior superior and inferior iliac spine (ASIS and AIIS) as bony landmarks, and the lateral and posterior parts that target fascia tensor, short rotators, and gluteus minimus, medius, and maximus with greater trochanter and ischial tuberosity as bony landmarks. The accuracy of diagnosing postoperative abnormalities and the visibility of periprosthetic muscles were compared between these two modalities. Both MRI and ultrasonography detected an abnormal region in eight cases comprising two infections, two pseudotumors, and four patients with greater trochanteric bursitis. Among these cases, four hips required implant removal. The increase in anterior space, measured as the distance between the iliopsoas and resurfacing head, was a good indicator for the abnormal mass in these four HRA cases. In the assessment of periprosthetic muscles, MRI showed a much lower visibility than ultrasonography in the iliopsoas (6.7% vs. 100%), gluteus minimus (6.7% vs. 88.9%), and short rotators (8.8% vs. 71.4%) due to implant halation. By targeting periprosthetic muscles, ultrasonography can detect postoperative complications as effectively as MRI assessments in HRA patients. Ultrasonography has superior visibility in the periprosthetic muscles of HRA patients, indicating its utility for the screening of small legions in these cases which may not be visible by MRI.

Revision risk by using the direct superior approach (DSA) for total hip arthroplasty compared with postero-lateral approach: early nationwide results from the Dutch Arthroplasty Register (LROI).

The direct superior approach (DSA) is a modification of the classic posterolateral approach (PLA) for total hip arthroplasty (THA), in which the iliotibial band and short external rotators are spared. The revision rate of the DSA has not been investigated previously using arthroplasty registry data. We examined the reasons and risk of revision of the DSA, compared with the direct anterior approach (DAA) and PLA. In this population-based cohort study we included 175,543 primary THAs performed between 2014 and 2020 (PLA, n = 117,576; DAA, n = 56,626; DSA, n = 1,341). Competing risk survival analysis and multivariable Cox proportional hazard analyses, adjusted for potential confounders, were performed. After 3 years, crude revision rates due to any reason were 2.1% (95% confidence interval [CI] 1.3-3.3) for DSA, and 2.9% (CI 2.8-3.0) for PLA. Crude dislocation revision rates were 0.3% (CI 0.1-0.8) for DSA, versus 1.0% (CI 0.9-1.0) for PLA. Dislocation revision rate for DSA did not differ from DAA (0.3% [CI 0.2-0.3]). Multivariable Cox regression analysis demonstrated no overall difference in revision rates for the DSA (HR 0.6 [CI 0.4-1.09) compared with the PLA. Lower risk of revision due to dislocation was found in patients operated on through the DSA (HR 0.3 [0.1-0.9]) compared with the PLA. Early nationwide results suggest that the DSA for total hip arthroplasty seems to show a tendency towards a lower risk of revision for dislocation but no overall reduced revision risk compared with the PLA.

Panoramic ultrasound imaging does not produce muscle morphology deformation during imaging acquisition: A validity study

PurposeDespite panoramic ultrasound imaging (US) is a promising advance for the morphological and histological assessment of large musculature which cannot be entirely assessed using B-mode, there is no evidence assessing if this technology produces muscle deformation during imaging acquisition. We aimed to analyze differences in size, shape and brightness descriptors between B-mode and panoramic US images and to assess the concordance between both methods.MethodsWe analyzed size (cross-sectional area and perimeter), shape (circularity, aspect ratio and roundness) and brightness (mean echo-intensity) features of cervical multifidus (CM) and short rotators (SR) in 46 healthy volunteers. Images were acquired in B-mode and extended field-of-view mode. For validity analysis, mean differences between methods were calculated. For agreement analysis, intraclass correlation coefficients (ICCs), standard error of measurements (SEM), minimal detectable changes (MDC) and coefficient of variation (CV%) were calculated. ResultsAll parameters showed no significant differences between both methods for either CM or SR (P > 0.05). Panoramic US showed excellent concordance with B-mode for assessing all CM parameters (all ICCs > 0.9), while for SR the agreement ranged from good-to-excellent (ICC from 0.861 to 0.978). ConclusionPanoramic US seems to be a valid tool for assessment of muscle size, shape and brightness as no deformation in comparison with B-mode images was seen. Further research is needed to corroborate these findings comparing panoramic US imaging with Gold Standard methods.

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

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. 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. 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. 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.

MANAGEMENT OF HIP DISLOCATION IN EMERGENCY DEPARTMENT

Hip dislocations following trauma are a common occurrence in the emergency room. Since the hip is a ball and socket joint with concomitant muscular and ligamentous attachments, it often takes a large amount of force to dislocate a hip. Due to the needed force, hip dislocations frequently come together with additional serious injuries. 90% of the time, hip trauma appears as a posterior dislocation when detected because the anterior ligaments are stronger. The rectus femoris, gluteal muscles, and short external rotators make up dynamic muscular support. 95% of patients who had a hip dislocation following a car accident also had an accompanying injury that needed hospital treatment. Therefore, a thorough neurologic and musculoskeletal evaluation with further x-rays or CT scans for assessment is required in cases with native hip dislocation. Standard AP (anteroposterior) scans of the pelvis often show hip dislocations clearly. However, a cross-table lateral of the injured joint is often included in comprehensive imaging. Hip dislocations can be more difficult to reduce than other types of dislocations, and most patients need procedural anaesthesia to make the reduction easier. Before considering surgical reduction, experts advise making up to three closed reduction efforts. However, 10% of hip dislocations may not be treatable in the emergency room and require surgical reduction under general anaesthesia.

Capsular Repair Counteracts the Risk of Dislocation in Hemiarthroplasty Conversion to Total Hip Arthroplasty.

This study investigated whether decreasing the femoral head size, in addition to performing a posterior capsular closure and short external rotator repair, influences the historical rate of dislocation after conversion of a failed hemiarthroplasty (HA) to a total hip arthroplasty (THA) through a posterior approach. We reviewed 15 patients from our prospective arthroplasty database who underwent a conversion from an HA to a THA with closure of the posterior capsule, had downsizing of the femoral head, and had at least a 2-year follow-up. Patients were clinically observed to determine whether their hip dislocated postoperatively or required re-revision. Radiographs were evaluated to assess for known risk factors for dislocation, including component position and restoration of hip biomechanics. The femoral head size was downsized from a mean of 45 mm (range, 42-57 mm) preoperatively to a mean of 32 mm (range, 28-36 mm) postoperatively (P<.001). Femoral heads sized 36, 32, and 28 mm were used in the revision of 4, 5, and 6 hips, respectively. At the mean 84-month follow-up (range, 24-156 months), there were no dislocations. Attention to surgical technique and closing the posterior capsule can decrease the historically high dislocation rate associated with converting an HA to a total hip replacement using the posterolateral approach. Despite substantial reduction in size of the prosthetic femoral head, there were no postoperative dislocations with closure of the posterior capsule. Downsizing the femoral head during revision THA should be avoided; however, if not feasible, closure of the posterior capsule can offset the otherwise increased risk of dislocation. [Orthopedics. 2023;46(3):175-179.].

The prevalence and risk factors of dislocation after primary total hip arthroplasty.

This study aimed to investigate the occurrence of dislocation and risk factors following primary total hip arthroplasty (THA). Retrospective analysis was done on the clinical data of 441patients with primary total hip arthroplasty who were admitted to our hospital between May 2018 and early December 2020. A total of 294 patients without posterior soft tissue repair were included as control group, and a total of 147 patients with repair of the short external rotator muscle and joint capsule were assigned to the repair group. All operated patients were observed to analyze the occurrence and risk of early postoperative dislocation. Within 6 months after hip arthroplasty, the early hip dislocation rate in the repair group was 0.68%, which was significantly lower than that in the control group (4.78%) (P < 0.05). The results of multifactorial analysis showed that age ≥75 years, combined limb or mental illness, artificial femoral head diameter <30 mm, posterolateral approach and prosthesis placement outside the safety zone, and improper handling were risk factors for dislocation (P < 0.05); The incidence of re-dislocation was lower in the targeted intervention group (P < 0.05). The occurrence of dislocation after THA is related to age, gender, and type of orthopedic disease. The risk factors should be explored to develop targeted intervention protocol, decreasing the dislocation rate and improving the prognosis.

The short external rotators in the anterior approach hip arthroplasty: do the tendons heal or not? A prospective MRI study.

Release of some of the short external rotator tendons may be needed in the direct anterior approach (DAA) for Total Hip Arthroplasty (THA). It is unknown if these tendons heal. The purpose of this prospective study is to examine short external rotator tendon healing after release and the associated effect on muscle volume. In addition, we examined the relation with external rotation force and patient reported outcome measures (PROMs). In 21 DAA THA patients, preoperative MRI was compared with postoperative MRI at 6 weeks and 12 months. PROMs and rotation force of both hips were assessed. Tendon integrity and muscle volume of the obturator internus and piriformis were assessed on MRI using dedicated software. In 5 patients all tendons remained intact, in 4 patients only the conjoined tendon was released and in 12 patients both the conjoined and piriformis were released. Obturator externus remained intact in all patients. In patients with tendon release, mean volume of obturator internus and piriformis muscle decreased 27% (SD 11) and 23% (SD 16) 6 weeks after surgery, respectively. Released tendons and muscle volume loss did not recover 12 months after surgery. We found no relation between tendon release and hip rotation force or PROMs. We found absent tendon healing and muscle volume loss when the conjoined or piriformis tendons were released. Although we found no relation between tendon detachment and hip force or PROMs, we have adapted our operative technique to make it more preserving for the piriformis.

An Updated Review on Layered Closure Techniques for Total Hip Arthroplasty.

One of the main concerns with total hip arthroplasty is the development of periprosthetic joint infections (PJIs). Appropriate wound closure can contribute to the prevention of PJIs with a watertight closure effectively sealing the implant from the outside. It is important to continuously investigate which materials as well as techniques are potentially the most efficacious and cost effective for wound closure. Therefore, the purpose of this review article was to critically appraise the current total hip arthroplasty wound closure materials and techniques as reported in the literature. Specifically, we evaluated: 1) fascial approximations; 2) subdermal closures; 3) subcuticular and skin closures; 4) wound dressings; as well as 5) capsular and short external rotator repairs. A literature search was performed using the PubMed database from inception to February 2022. The query consisted of terms including "hip, arthroplasty, wound, closure, capsular closure, fascial closure, subcutaneous closure, and skin closure." References from selected texts were also reviewed for inclusion. Only manuscripts written in the English language were included for final analysis. A systematic review was performed for the five topics: 1) fascial approximations; 2) subdermal closures; 3) subcuticular and skin closures; 4) wound dressings; as well as 5) capsular and short external rotator repairs. Additionally, a meta-analysis was performed on the closing time of fascial approximations. The current literature supports performing a layered closure of the wound by approximating the fascial layers, which can help close any empty spaces. The techniques for closure at this layer seem to be equal regarding wound complications between running knotless barbed sutures versus interrupted throws; however, knotless sutures have the potential of a quicker closure time. A total of three out of four reports and the meta-analyses demonstrated that wound closure time can be reduced with barbed sutures, along with decreased number of sutures required as also shown by three out of four reports. The most superficial layers, subcuticular and skin, can be closed with either sutures, staples, or skin adhesives, all of which appear to have adequate outcomes. A report found that patients who had skin closure with barbed suture had faster time to a dry postoperative wound and lower rates of delayed discharge. For the overlying dressing, an occlusive and absorbent dressing can both protect the wound as well as collect any residual wound drainage. Two reports found increased dryness, decreased wound drainage, and decreased rates of delayed wound healing with use of 2-octyl cyanoacrylate topical adhesive with flexible self-adhesive polyester mesh dressings. If the capsule and short external rotators are taken down during the approach, repairing these can potentially help increase postoperative hip stability as well as decrease dislocation rates. The variety of materials and techniques available to close a THA wound allows surgeons to tailor closure to be patient specific. In general, the authors recommend performing layered closures from the capsule and short external rotators (if taken down during the approach), fascial layer closure with either a running knotless suture, subcutaneous closure either with the same knotless suture as the fascial layer brought more superficially, or with simple interrupted sutures to tack down any empty space, as well as finally subcuticular and skin sutures with a skin adhesive glue overtop. The skin adhesive can help provide an extra layer, particularly in active patients.