Does lesser trochanter implication affect hip flexion strength in proximal femur fracture?

Intertrochanteric femoral fracture with lateral wall fracture at the lag screw insertion site may cause postoperative anterior wall fracture and lead to deterioration in activities of daily living

BACKGROUND

Incomplete reduction and fixation of intertrochanteric femoral fractures significantly affect patients' daily activities. The lateral wall's integrity is pivotal in such fractures. This study examines instability, particularly lateral wall fractures at the lag screw insertion site and postoperative anterior wall fractures.

METHODS

Overall, 161 patients with femoral intertrochanteric fractures were included. Three-dimensional computed tomography was conducted preoperatively and 3 weeks postoperatively to determine the postoperative anterior wall fractures incidence. Patient background, operative time, intraoperative blood loss, postoperative telescoping, and daily living activities were compared.

RESULTS

The study recorded 51 cases of lateral wall fractures at the lag screw insertion site and 17 of postoperative fractures of the anterior wall. Postoperative fractures of the anterior wall were found in 3 of 110 and 14 of 51 patients in the group without and with the lag screw insertion site, respectively. The group of postoperative fractures of the anterior wall had significantly lower bone mineral density, longer operative time, and increased intraoperative blood loss. At 4 weeks postoperatively, the group of postoperative fractures of the anterior wall showed increased telescoping and decreased motor component of the functional independence measure (with postoperative fractures of the anterior wall: 28, without postoperative fractures of the anterior wall: 30), and significant reductions were observed in the transfer and locomotion items, indicating lower limb function (with postoperative fractures of the anterior wall group: 11, without postoperative fractures of the anterior wall group: 12).

CONCLUSIONS

Postoperative anterior wall fractures occurred in 27.5% cases with lateral wall fractures at the lag screw insertion site. Three-dimensional computed tomography is useful for preoperative evaluation of lateral wall fractures at the lag screw insertion site to assess instability. Postoperative fractures of the anterior wall related reduction in daily living activities needs attention.

Biomechanical comparison of screw vs. cerclage refixation in orthogeriatric lesser trochanteric fractures: a cadaveric study

PURPOSE

Osteoporosis-related proximal femur fractures continue to increase significantly due to demographic change. This study was designed to evaluate the biomechanical stability of two different fixation methods (cerclage vs. screw) for refixation of a trochanter minor fragment in the pertrochanteric fractures in cadaveric bones.

METHODS

Artificial bones (n = 14) and human bones (n = 16) were treated with a DHS and the trochanter minor fragment was reduced by cerclage wiring or direct screw fixation. After preloading the simulated iliopsoas with 10 N, a tensile test was performed, ending with either a 70% loss of strength or avulsion of the fragment. The mean values of the avulsion force and the surface strain were recorded.

RESULTS

All tensile tests showed no significant differences between refixation using a direct screw or wire cerclage, for both artificial bones and human specimens. Absolute values showed higher avulsion forces after direct screw fixation than refixation with a wire cerclage. The surface tension of specimens treated with direct screw fixation was lower than that of specimens treated with wire cerclage. An opposite effect was seen in artificial bones. Both effects were not statistically significant.

CONCLUSION

Based on the equal stability after lag screw placement compared to cerclage wiring, we promote the placement of a lag screw into the lesser trochanter fragment in pertrochanteric femur fractures when using a dynamic hip screw.

LEVEL OF EVIDENCE

Level III.

A comprehensive 3D CT based classification of intertrochanteric fracture

Introduction

Despite advancements in surgical techniques complications like implant failure is very common after the fixation of intertrochanteric fractures. Classifying these complex fractures based on plain radiographs underestimates the complexity of these fractures which in turn leads to complications. We propose a comprehensive classification of the intertrochanteric fractures based on 3D Non Contrast Computed Tomography (3D NCCT) scan.

Material and methods

A total of 102 patients (51 males and 51 females) with intertrochanteric fractures were included in this study conducted over a time period of 22 months in a Tertiary care center in North India. NCCT proximal femur of the intertrochanteric fracture patients was done to formulate a new CT classification system and classify all fractures. Intra and inter-observer reliability was tested using kappa variance.

Results

New classification system was proposed which included 3 main and a total of 6 groups. All the fractures were classifiable into the new system. Kappa variance of the study showed a good intra and interobserver reliability (0.95 and 0.90) proving clinical agreement of the classification.

Conclusion

This new 3D-CT based classification has the advantages of being easy, comprehensible with high intra and inter-observer reliability. This 3DCT based classification can prove to be useful to detect occult intertrochanteric fractures undetectable in plain radiographs as well as choosing the optimum treatment plan.

Tuberculosis Challenging Pathognomicity of Atraumatic Avulsion of the Lesser Trochanter for Malignancy: A Rare Case Report

CASE

A 40-year-old man presented with spontaneous, atraumatic right groin pain and inability to bear weight secondary to an isolated avulsion of the right lesser trochanter. Magnetic resonance imaging of the affected hip was suggestive of an infection, and a computed tomography-guided biopsy was remarkable for Mycobacterium tuberculosis, which was successfully managed with antitubercular therapy and activity modification.

CONCLUSION

Although an isolated spontaneous avulsion of the lesser trochanter is typically pathognomonic for malignancy, an infectious etiology, such as tuberculosis, should also be considered in the differential diagnosis.

When to Reduce and Fix Displaced Lesser Trochanter in Treatment of Trochanteric Fracture: A Systematic Review

Purpose

To systematically evaluate the benefits of reducing and fixing displaced lesser trochanter (LT) of trochanteric fractures and when this procedure is worth the effect.

Methods

From database establishment through March 2021, four online databases (PubMed, Cochrane, Embase, and Web of Science) were searched for relevant literature that investigated reduction and fixation for displaced LT of trochanteric fractures. The papers were then screened by two reviewers independently and in duplicate according to prior inclusion and exclusion criteria. Demographic data as well as data on fracture types, surgical protocols, and surgical outcomes were recorded, analyzed, and interpreted.

Results

Total 10 clinical studies with 928 patients were included, in which 48 cases had intact LT and 880 cases involved the displaced LT, of which 196 (22.27%) cases underwent reduction and fixation for LT while the rest of 684 (77.73%) cases not. In these studies, complications were evaluated as a more applicable predictive parameter for operation than postoperative hip function.

Conclusion

It was beneficial to reduce and fix the displaced LT when one of the conditions below occurred: displacement distance of LT ≥2 cm, quantity of comminuted LT fragments ≥2, and range of LT fragments in medial wall ≥75%; the fracture line of LT fragments reaching or exceeding the midline of the posterior wall.

In Silico Finite Element Modeling of Stress Distribution in Osteosynthesis after Pertrochanteric Fractures

A stabilization method of pertrochanteric femur fractures is a contentious issue. Here, we assess the feasibility of rapid in silico 2D finite element modeling (FEM) to predict the distribution of stresses arising during the two most often used stabilization methods: gamma nail fixation (GNF) and dynamic hip screw (DHS). The modeling was based on standard pre-surgery radiographs of hip joints of 15 patients with pertrochanteric fractures of type A1, A2, and A3 according to the AO/OTA classification. The FEM showed that the stresses were similar for both GNF and DHS, with the medians ranging between 53-60 MPa and consistently lower for A1 than A3 fractures. Stresses also appeared in the fixation materials being about two-fold higher for GNF. Given similar bone stresses caused by both GNF and DHS but shorter surgery time, less extensive dissection, and faster patient mobilization, we submit that the GNF stabilization appears to be the most optimal system for pertrochanteric fractures. In silico FEM appears a viable perioperative method that helps predict the distribution of compressive stresses after osteosynthesis of pertrochanteric fractures. The promptness of modeling fits well into the rigid time framework of hip fracture surgery and may help optimize the fixation procedure for the best outcome. The study extends the use of FEM in complex orthopedic management. However, further datasets are required to firmly position the FEM in the treatment of pertrochanteric fractures.

Inferior Outcome after Unstable Trochanteric Fracture Patterns Compared to Stable Fractures in the Elderly

BACKGROUND

Various risk factors affecting outcome of elderly patients after proximal femur fracture have been identified. The present study aims to evaluate the impact of the fracture pattern in trochanteric fractures on postoperative mobility and complications.

METHODS

Ninety-two patients with a mean age of 84 years were included. According to the revised AO/OTA classification, fractures were divided into stable (AO 31A1) and unstable (AO 31A2/3) patterns. A follow-up examination was performed 12 months after cephalomedullary fixation to assess outcome parameters for mobility/activities of daily living (Parker Mobility Score (PMS)/Barthel Index (BI)) and complications (increase in requirement of care, hospital readmission, mortality rate).

RESULTS

At follow-up, patients with unstable trochanteric fracture patterns presented with lower PMS and BI compared to stable fractures (p < 0.05). Further, higher requirement of care and higher readmission rates compared to stable patterns were observed.

CONCLUSION

Unstable trochanteric fractures presented inferior outcome compared to simple fracture patterns. This might be explained by the increasing surgical trauma in unstable fractures as well as by the mechanical impact of the lesser trochanter, which provides medial femoral support and is of functional relevance. Subsequent studies should assess if treatment strategies adapted to the specific fracture pattern (refixation of lesser trochanter) influence outcome in unstable trochanteric fractures.

Impact of Bone Fracture on Muscle Strength and Physical Performance-Narrative Review

PURPOSE OF REVIEW

Low muscle strength and poor physical performance are associated with high risk of fracture. Many studies assessed clinical and functional outcomes of fractures. Fewer studies analyzed the impact of fractures on muscle strength and physical performance.

RECENT FINDINGS

Vertebral fractures (especially multiple and severe ones) are associated with back pain, back-related disability, lower grip strength, lower strength of lower limbs, lower gait speed, and poor balance. Patients with hip fracture have slower gait and lower quadriceps strength. Non-vertebral fractures were associated with lower strength of the muscles adjacent to the fracture site (e.g., grip strength in the case of distal radius fracture, knee extensors in the case of patellar fracture) and poor physical function dependent on the muscles adjacent to the fracture site (e.g., limited range of motion of the shoulder in the case of humerus fracture, gait disturbances in the case of the ankle fracture). Individuals with a fracture experience a substantial deterioration of muscle strength and physical performance which exceeds that related to aging and is focused on the period close to the fracture occurrence. After fracture, muscle strength increased and physical performance improved. The rate of normalization depended partly on the therapeutic approach and on the rehabilitation program. A subgroup of patients, mainly the elderly, never returns to the pre-fracture level of physical performance. The permanent decline of physical function after fracture may be related to the limitation of movements due to pain, low physical activity, poor health before the fracture, and reduced efficacy of retraining after immobilization.

The functional effect of lesser trochanter involvement in hip fractures: A prospective cohort study

INTRODUCTION

Hip fractures are the most common fractures amongst frail older patients. Earlier studies have indicated an impaired hip flexion strength in patients with fractures that include detachment of the lesser trochanter. These patients may experience protracted functional impairment and longer recovery time, causing prolonged rehabilitation journeys. This study aimed to evaluate the effects of a detached lesser trochanter in trochanteric fractures on the recovery of hip function.

METHOD

A prospective observational cohort study was performed between 2016 and 2019. Community dwelling patients aged 70 years or older with AO 31A1-A3 trochanteric fractures were included. Patients followed routine care and were treated with a DHS or PFNA. The groups with and without involvement of the lesser trochanter were analysed. The primary outcome was hip function assessed at 6 weeks, 3 months and 1 year after surgery with the Harris Hip Score. Secondary outcomes included the Ludloff's test, complications, rehabilitation time, and pain-, independence-, and quality of life scores. A propensity score was used to adjust for any baseline differences between the two groups.

RESULTS

A total of 114 patients were included, 51 (44.7%) with involvement of the lesser trochanter and 63 (55.3%) without. Minor differences were observed in the baseline characteristics. No significant difference was observed for the Harris Hip Score (coefficient estimate: 3.31; 95% CI, -5.09-11.72; P = 0.43). The flexion function of the iliopsoas muscle was more often normal with the Ludloff's test in patients without involvement of the lesser trochanter (OR, 2.33; 95% CI, 1.241-4.387; P = 0.009). However, no differences were observed for any of the other secondary outcomes.

CONCLUSION

Although no differences in overall hip function were found, more hip fracture patients with involvement of the lesser trochanter showed prolonged impaired flexion of the hip. The absence of long-term, clinically relevant disadvantages however, proves fixing the lesser trochanter to be redundant.

Effect of types of proximal femoral fractures on physical function such as lower limb function and Activities of Daily Living

OBJECTIVES

This study aimed to assess physical function such as lower limb function and Activities of Daily Living after surgery for proximal femoral fractures ( unstable medial femoral neck fracture and trochanteric fracture).

METHODS

This study enrolled 68 patients with proximal femoral fractures. Isometric knee extension strength (IKES), the Japanese Orthopedic Association (JOA) hip score, and the number of days required to develop straight leg raising, transfer, and T-caneassisted gait abilities to become independent were assessed. Patients were classified based on the types of proximal femoral fractures, namely unstable medial femoral neck fracture (bipolar hip arthroplasty [BHA] group), stable trochanteric fracture (S group), and unstable trochanteric fracture (US group).

RESULTS

IKES and the JOA hip score were significantly better in the BHA group than in the S and US groups. IKES and the JOA hip score were significantly worse in the US group than in the BHA and S groups. Both transfer and T-cane-assisted gait abilities of patients in the BHA and S groups were indifferent. However, all physical functions were significantly worse in the US group.

CONCLUSIONS

Our study results suggested that physical therapists plan the different rehabilitation program for the patients with proximal femoral fractures who were classified into three types, namely unstable medial femoral neck fracture, stable trochanteric fracture, and unstable trochanteric fracture, instead of two types.

Effect of lesser trochanter posteromedial wall defect on the stability of femoral intertrochanteric fracture using 3D simulation

BACKGROUND

This study investigated the effects of posteromedial fracture fragments on the postoperative stability of intertrochanteric fractures of the femur by analyzing the quantity and range of fragments in CT 3D reconstruction.

MATERIALS AND METHODS

Patients diagnosed with femoral lesser trochanter fractures were collected from September 2015 to February 2018. CT 3D reconstruction was applied to evaluate the quantity and extension of posteromedial fragments and the presence of isolated medial fragments. The stability of postoperative fracture was evaluated by comparing the changes of "neck-shaft angle" and "telescoping" from 1 week to 1 year after operation.

RESULTS

A total of 143 patients were finally confirmed, in which 63 patients contained isolated fragments on the medial side, and the average number of fragments in the posteromedial side was 1.93 ± 0.34, which accounted for an average of about 86.11% ± 8.20% in the whole posteromedial wall. When the number of posteromedial fragments was > 2 and the range of posteromedial fragments was > 75%, then the changes in the neck-shaft angle and "telescoping" showed statistical significance (12.27 ± 4.18 mm and 10.13 ± 6.17°, respectively), and when there were isolated medial isolated fragments, then the change in the neck-shaft angle was 10.66 ± 4.27°, showing statistical significance.

CONCLUSIONS

These findings revealed a certain correlation between the quantity and the range of posteromedial fragments and the postoperative "shortening" and "collapse" of femoral intertrochanteric fractures.

Anatomy-based MRI assessment of the iliopsoas muscle complex after pertrochanteric femoral fracture

OBJECTIVE

To evaluate the quality of the iliopsoas muscle complex after pertrochanteric femoral fracture, using MRI; to propose an anatomy-based evaluation of the iliopsoas muscle complex; and to determine the inter-reader reliability of two classifications of fatty muscle degeneration.

MATERIALS AND METHODS

We included adult patients with a displaced lesser trochanter following pertrochanteric femoral fracture. Muscle quality was evaluated using the Goutallier and Slabaugh classifications at three levels (L4/L5, L5/S1, and the anterior inferior iliac spine). Two radiologists independently reviewed the MRIs, and force measurement was performed on both hips. Linear mixed-effects models were used to determine the effect of fracture on muscle quality and strength, and Cohen's kappa statistic was used to assess inter-reader agreement.

RESULTS

In the 18 patients included, the iliopsoas muscle complex showed higher grades of fatty muscle degeneration on the fractured side than on the non-fractured side. The mean difference between muscle strength on the fractured vs the non-fractured side was -12 N (p > 0.05). Inter-reader agreement for the Goutallier and Slabaugh classifications was good and very good respectively (weighted K = 0.78 and 0.85 respectively).

CONCLUSION

Fatty muscle degeneration of the iliopsoas muscle complex after pertrochanteric femoral fracture was evident using both classification systems; however, fatty muscle degeneration resulted in only a minimal reduction of muscle strength. To provide a thorough assessment of iliopsoas muscle complex quality, we suggest evaluating it at different anatomical levels. Regarding inter-reader agreement, the Slabaugh classification was superior to the Goutallier classification.

[Isolated fracture of the lesser trochanter-What age-related differences are important?]

Isolated fractures of the lesser trochanter are very rare injuries. This case report describes the age-related differences based on two cases. A 13-year-old girl suffered an avulsion fracture of the lesser trochanter while sprinting. The patient received conservative treatment with pain-adapted partial weight bearing as tolerated using crutches with the goal of full weight bearing after 6 weeks. After 3 months she could return to the preinjury functional level without impairments. A 55-year-old woman also suffered an isolated fracture of the lesser trochanter, which was a pathological fracture due to a breast cancer metastasis. The cause of an isolated fracture of the lesser trochanter in adults is assumed to be the sign of an underlying malignant disease, until this has been disproven.

Avulsion fracture of the lesser trochanter in adolescents

INTRODUCTION

Avulsion fractures of the lesser trochanter in adolescents are rare. They are a result of a sudden and forceful contraction of the iliopsoas muscle. Functional results in the medium term after non-operative treatment are unknown. Therefore we aimed to report these in the present study.

MATERIALS AND METHODS

A retrospective two-center study was performed in a case series treated between 2011 and 2017. All adolescents with an acute avulsion fracture of the lesser trochanter were included. Age, gender, mechanism of injury, fracture side, amount of displacement, and therapy were analyzed. In the follow-up, the Harris Hip Score (HHS), the sports level, the power of flexion in the hip, and signs of an ischio-femoral impingement (IFI) were investigated.

RESULTS

An avulsion fracture of the lesser trochanter was diagnosed in 4 boys and 1 girl. The mean age of the patients was 13.8 years (range: 13-15 years). We observed 2 type II and 3 type III fractures. The patients received similar non-operative treatment. Follow-up was performed at a mean of 4.9 years (range: 3.5-6.2 years) after injury. All patients returned to competitive sports. The Harris Hip Score (HHS) was 100 out of 100 points. History and provocation test concerning an IFI were negative in all patients.

CONCLUSION

Our study shows excellent results with non-operative treatment in acute avulsion fractures of the lesser trochanter in a case series of five adolescents. All patients returned to competitive sports. In our opinion, acute avulsion fractures of the lesser trochanter should be treated non-operatively.

No difference in flexion power despite iliopsoas fatty degeneration in healed hip fractures with large lesser trochanter displacement

Objective

To evaluate iliopsoas atrophy and loss of function after displaced lesser trochanter fracture of the hip.

Design

Cohort study.

Setting

District hospital.

Patients

Twenty consecutive patients with pertrochanteric fracture and displacement of the lesser trochanter of > 20 mm.

Intervention

Fracture fixation with either an intramedullary nail or a plate.

Outcome measurements

Clinical scores (Harris hip, WOMAC), hip flexion strength measurements, and magnetic resonance imaging findings.

Results

Compared with the contralateral non-operated side, the affected side showed no difference in hip flexion force in the supine upright neutral position and at 30° of flexion (205.4 N vs 221.7 N and 178.9 N vs. 192.1 N at 0° and 30° flexion, respectively). However, the affected side showed a significantly greater degree of fatty infiltration compared with the contralateral side (global fatty degeneration index 1.085 vs 0.784), predominantly within the psoas and iliacus muscles.

Conclusion

Severe displacement of the lesser trochanter (> 20 mm) in pertrochanteric fractures did not reduce hip flexion strength compared with the contralateral side. Displacement of the lesser trochanter in such cases can lead to fatty infiltration of the iliopsoas muscle unit. The amount of displacement of the lesser trochanter did not affect the degree of fatty infiltration.

Level of evidence

II.

The role of lesser trochanter fragment in unstable pertrochanteric A2 proximal femur fractures - is refixation of the lesser trochanter worth the effort?

BACKGROUND

Instability of osteoporotic pertrochanteric fractures is defined by loss of medial/lateral cortical integrity with the posteromedial fragment including the lesser trochanter being pivotal for load distribution. Literature addressing the importance of lesser trochanter refixation is scarce. To clarify the effect of lesser trochanter refixation on primary stability in these fractures, following study was performed.

METHODS

21 femora were match-paired in 3 groups and osteotomized, creating pertrochanteric fractures (AO-31A2). Group 1 was stabilized with a proximal femoral nail, group 2 with a dynamic hip screw and group 3 with an augmented proximal femoral nail. Each femur was tested non-destructively at 200 and 400N with and without refixation of the lesser trochanter (configuration A/B). The overall stiffness and movement of the femoral neck was recorded.

FINDINGS

At 200N, refixation reduced movement of the femoral neck and increased overall stiffness significantly in group 1 and 3. At 400N, refixation decreased movement of the femoral neck not significantly in all groups (1=38%, 2=36%, 3=43%). The augmented proximal femoral nail after refixation showed the highest stability of all constructs.

INTERPRETATION

Refixation of the lesser trochanter may increase the primary stability of pertrochanteric fracture osteosynthesis as all groups showed a higher primary stability. Therefore, refixation should be considered in unstable, osteoporotic fractures. If additional trauma through refixation appears inappropriate, cement augmentation should be performed as it showed only 9% less stability than a non-augmented proximal femoral nail with refixation of the lesser trochanter.