With the increasing use of primary hip arthroplasty for management of intertrochanteric fractures, firm fixation and union of the greater trochanteric (GT) fragment are required during hip arthroplasty for management of intertrochanteric fractures. Various methods have been suggested to address this issue. However, displacement of the GT is a frequent occurrence. We have introduced a cement-filling technique for performance of hip arthroplasty of the proximal femur for achievement of immediate firm fixation of the GT. Cement filling during performance of hip arthroplasty for management of femoral intertrochanteric fractures is a valuable technique for preventing displacement of the GT and to encourage early mobilization.

In patients with total hip arthroplasty (THA) with recurrent pain, symptoms may be caused by several conditions involving not just the joint, but also the surrounding soft tissues including tendons, muscles, bursae, and peripheral nerves. US and US-guided interventional procedures are important tools in the diagnostic work-up of patients with painful THA given that it is possible to reach a prompt diagnosis both directly identifying the pathological changes of periprosthetic structures and indirectly evaluating the response and pain relief to local injection of anesthetics under US monitoring. Then, US guidance can be used for the aspiration of fluid from the joint or periarticular collections, or alternatively to follow the biopsy needle to collect samples for culture analysis in the suspicion of prosthetic joint infection. Furthermore, US-guided percutaneous interventions may be used to treat several conditions with well-established minimally invasive procedures that involve injections of corticosteroid, local anesthetics, and platelet-rich plasma or other autologous products. In this review, we will discuss the clinical and technical applications of US-guided percutaneous interventional procedures in painful THA that can be used in routine daily practice for diagnostic and therapeutic purposes.

Insect legs play a crucial role in various modes of locomotion, including walking, jumping, swimming, and other forms of movement. The flexibility of their leg joints is critical in enabling various modes of locomotion. The frog-legged leaf beetle Sagra femorata possesses remarkably enlarged hind legs, which are considered to be a critical adaptation that enables the species to withstand external pressures. When confronted with external threats, S. femorata initiates a stress response by rapidly rotating its hind legs backward and upward to a specific angle, thereby potentially intimidating potential assailants. Based on video analysis, we identified 4 distinct phases of the hind leg rotation process in S. femorata, which were determined by the range of rotation angles (0°-168.77°). Utilizing micro-computed tomography (micro-CT) technology, we performed a 3-dimensional (3D) reconstruction and conducted relative positioning and volumetric analysis of the metacoxa and metatrochanter of S. femorata. Our analysis revealed that the metacoxa-trochanter joint is a \"screw-nut\" structure connected by 4 muscles, which regulate the rotation of the legs. Further testing using a 3D-printed model of the metacoxa-trochanter joint demonstrated its possession of a self-locking mechanism capable of securing the legs in specific positions to prevent excessive rotation and dislocation. It can be envisioned that this self-locking mechanism holds potential for application in bio-inspired robotics.

Bike fitting aims to optimize riders\' positions to improve their performance and reduce the risk of injury. To calculate joint angles, the location of the joint centers of the lower limbs needs to be identified. However, one of the greatest difficulties is the location of the hip joint center due to the frequent occlusion of the anterior superior iliac spine markers. Therefore, the objective of this study was to validate a biomechanical model adapted to cycling (modified pelvic model, MPM), based on the traditional pelvic model (TPM) with an additional lateral technical marker placed on the iliac crests. MPM was also compared with a widely used model in cycling, trochanter model (TM). Thirty-one recreational cyclists pedaled on a roller bike while the movement was captured with a 7-camera VICON system. The position of the hip joint center and knee angle were calculated and compared with the TPM continuously (along 10 pedaling cycles) and discreetly at 90° and 180° crank positions. No significant differences were found in the position of the hip joint center or in the knee flexion/extension angle between the TPM and the MPM. However, there are differences between TPM and TM (variations between 4.1° and 6.9° in favor of the TM at 90° and 180°; P < .001). Bland-Altman graphs comparing the models show an average difference or bias close to 0° (limits of agreement [0.2 to -8.5]) between TPM and MPM in both lower limbs and a mean difference of between -4° and -7° (limits of agreement [-0.6 to -13.2]) when comparing TPM and TM. Given the results, the new cycling pelvic model has proven to be valid compared with the TPM when performing bike fitting studies, with the advantage that the occluded markers are avoided. Despite its simplicity, the TM presents measurement errors that may be relevant when making diagnoses, which makes its usefulness questionable.

OBJECTIVE: Many studies have been conducted to evaluate the effects of nail shape, design, or length on the treatment of intertrochanteric fractures. However, the clinical implications of the nail diameter remain unclear.
METHODS: This study was conducted with 191 patients aged ≥ 50 years with unilateral intertrochanteric fractures treated with the same type of short cephalomedullary nail and followed for at least one year. We recorded the reduction type, tip-apex distance, cortical contact of the nail, and nail/canal diameter ratio (NCR) just distal to the locking screw. The effects of nail diameter on the clinical results were evaluated.
RESULTS: The average NCR was 68.7. The average union time was 4.78 months. Delayed union or nonunion was seen in 17 patients. Eight patients underwent additional surgery. The mean change in the modified Koval activity score was -0.84. The NCR did not significantly affect the clinical results. Comparisons of cases with NCRs above and below the average and the average - 1 standard deviation revealed no significant difference. The clinical outcome was not related to any variable associated with the nail diameter.
CONCLUSIONS: With this specific proximal femoral nail, a small diameter relative to that of the femoral canal had no adverse effect on the union of osteoporotic intertrochanteric fractures, even in patients with unstable fractures and those who had unsatisfactory reductions.

BACKGROUND: Various reconstruction options have been introduced to treat decubitus ulcers. A combined flap that takes advantage of the fasciocutaneous and muscle flaps has been proven to be effective in reconstructing decubitus ulcers in previous studies. However, no studies have measured combined flap thickness. This is the first study to demonstrate the superiority of the combined flap by measuring its thickness using enhanced abdominopelvic computed tomography (APCT).
OBJECTIVE: To evaluate combined flap modality as a useful reconstruction option for decubitus ulcers using measurements obtained through APCT.
METHODS: Fifteen patients with paraplegia who underwent combined flap surgery for reconstruction of decubitus ulcers between March 2020 and December 2021 were included. The defects in the skin and muscle components were reconstructed separately. The inner gluteus muscle flap was split and manipulated to obliterate dead space. The outer fasciocutaneous flap was transposed to cover the muscle flap and opening of the decubitus ulcer. Subsequently, we performed enhanced APCT at 3 wk and 6 mo postoperatively to measure the flap thickness.
RESULTS: The mean flap thickness was 32.85 ± 8.89 mm at 3 wk postoperatively and 29.27 ± 8.22 mm at 6 mo postoperatively. The flap thickness was maintained without any major complications such as contour deformities or recurrence.
CONCLUSIONS: Although there was a significant decrease in flap thickness as measured by APCT, the combined flap provided sufficient padding and maintained its thickness even at 6 mo after reconstruction, suggesting that the combined flap modality may be a useful reconstruction option for patients with paraplegic decubitus ulcers.

Avulsion of the lesser trochanter is a rare but disturbing condition, which usually occurs in males between the ages of 7-16 years with significant physical activities or in athletes. Diagnosis is more often than not challenging, but with a good history, physical examination, and imaging modality, diagnosis can be clinched, and the prognosis is good even with a conservative management approach. This case report is that of a 12-year-old male who suddenly fell while participating in sporting activities in school. As a consequence of the fall, he felt severe pain in the left groin region with an associated inability to bear weight on the affected limb. A radiograph study of the hip revealed a fracture of the left lesser trochanter. Based on the diagnosis, a conservative approach, which entails the use of analgesics, and partial weight-bearing mobilization with axillary crutches to take the weight off the affected limb for a period, was the choice of management for this subject. Fifteen weeks following the conservative management for the avulsion of the left femoral lesser trochanter fracture, the subject sustained a similar injury to the contralateral groin, consequential to return to sporting activities. In conclusion, rare as avulsion of the lesser trochanter may be, a high index of suspicion must be raised in any adolescent with a painful limp following engagement in any sporting activities, and such individuals should have a radiograph study done to achieve prompt and effective care.

Maintaining continuity of the greater trochanter and restoring abductor function are of paramount importance in primary and revision total hip arthroplasty. Failure to rigidly fix the greater trochanter can lead to failure. Because of the lack of reports on the clinical results of greater trochanter fixation with a claw plate and cable system, we aimed to analyze the indications for the use of such a system that produces the best clinical results.
We retrospectively studied 41 consecutive patients who had undergone primary or revision total hip arthroplasty at our institution between January 2004 and December 2014 using a claw plate and cable system to achieve stable fixation of the greater trochanter.
The mean follow-up duration was ten years. The median Harris hip score improved from 47 points before surgery to 87 points after surgery (p < 0.01). Significant improvements were observed in the range of motion, hip function, and routine activity. Osseous and fibrous union occurred in all patients, and one patient had severe complications (sciatica). Based on the Beals and Tower classification, 67%, 21%, and 13% of outcomes were considered excellent, good, and poor, respectively.
Our data support the use of a claw plate and cable system for greater trochanter fixation in complex primary and revision hip arthroplasty. The system showed promising results in patients with floating greater trochanters, intertrochanteric fractures requiring extra devices to maintain rotational stability, and extended trochanteric osteotomy fragments with a weakened proximodistal junction. The use of this system should be further investigated and compared to other methods.

OBJECTIVE: This study aims to answer the following questions in patients with hip osteoarthritis (OA) who underwent total hip arthroplasty (THA): are patient-reported outcome measures (PROMs) affected by the location of the maximum severity of pain?; are PROMs affected by the presence of non-groin pain?; are PROMs affected by the severity of pain?; and are PROMs affected by the number of pain locations?
METHODS: We reviewed 336 hips (305 patients) treated with THA for hip OA from December 2016 to November 2019 using pain location/severity questionnaires, modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), international Hip Outcome Tool (iHOT-12) score, and radiological analysis. Descriptive statistics, analysis of covariance (ANCOVA), and Spearman partial correlation coefficients were used.
RESULTS: There was a significant difference in iHOT-12 scores between groups experiencing the most severe pain in the groin and the trochanter (p = 0.039). Additionally, more favourable mHHS scores were related to the presence of preoperative pain in trochanter (p = 0.049), lower back (p = 0.056), lateral thigh (p = 0.034), and posterior thigh (p = 0.005). Finally, the maximum severity of preoperative pain and number of pain locations had no significant relationship with PROMs (maximum severity: HHS: p = 0.928, HOS: p = 0.163, iHOT-12 p = 0.233; number of pain locations: HHS: p = 0.211; HOS: p = 0.801; iHOT-12: p = 0.112).
CONCLUSIONS: Although there was a significant difference in iHOT-12 scores between patients with the most severe pain in the groin or trochanter, and the presence of pain in the trochanter, lower back, lateral thigh, or posterior thigh was related to higher mHHS scores, the majority of preoperative pain characteristics did not have a significant impact on outcomes. Therefore, a broad array of patients with hip OA might expect similar, favourable outcomes from THA notwithstanding preoperative pain characteristics. Cite this article: Bone Jt Open 2022;3(4):332-339.

BACKGROUND: Approximately 10-15% of the population over the age of 60 suffers from hip pain. Greater trochanteric pain syndrome (GTPS) is one of the most common diagnoses in patients with chronic hip pain, includes a number of disorders, and has a broad differential diagnosis. Conservative managements of GTPS, including pharmacologic interventions, physical therapy, chiropractic intervention, acupuncture, and more invasive techniques, such as intra-articular injections, commonly fail to provide patients with sufficient, long-term relief. While radiofrequency ablation (RFA) has been used to treat intra-articular hip pain in the past, there is little evidence for the feasibility of RFA for managing patients with GTPS. This case series builds on previous evidence that cooled radiofrequency ablation (CRF) of the trochanteric branch of the femoral nerve may offer patients with GTPS effective, safe, and lasting pain improvement.
METHODS: A series of eight patients with GTPS underwent CRF of the nervus females to the trochanter. CRF procedures were either targeted at the left, right, or bilateral nerves.
CONCLUSIONS: This case series provides additional evidence for the safety and effectiveness of CRF of the nervus femoralis to the trochanter for offering long-term pain relief in patients with GTPS. All patients experienced at least two months of relief, with most patients experiencing ongoing relief from the procedure.