Reverse Oblique Intertrochanteric Fractures Research Articles

Three different interlocking intramedullary nails for unstable reverse oblique inter-trochanteric fractures: a bio-mechanical comparative study

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">Biomechanical testing, intramedullary devices have proven advantageous over the extramedullary devices in the management of unstable intertrochanteric fractures. Reverse oblique type of intertrochanteric fractures are highly unstable and intramedullary nails are currently the method of internal fixation. The currently available nails seems to provide rotational, axial and angular stability, but biomechanical analysis of the strain pattern in the bone and implant in this fractures are lacking. The aim of this experimental study was to analyse the strain in three different long femoral nail-bone units under physiological loading when implanted in Saw bone model after creating a reverse oblique intertrochanteric fracture.</span></p><p class="abstract"><strong>Methods:</strong> A total of 12 sawbones were divided in to 4 equal groups. Group 1 was intact saw bones and were used as controls. Group 2, Group 3 and Group 4 were implanted with Depuy, Stryker and Synthes nails respectively after creating a reverse oblique intertrochanteric fracture. All the four groups were axially loaded with 100 N increments until physiological loads. The strain patterns were measured at the posteromedial cortex and the peak strains were extracted at partial weight bearing i.e. 500 N and full weight bearing physiological loads i.e. 1000 N.<strong></strong></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">There was no significant difference in peak strains among the groups at partial loads. However at 1000 N loads the peak strain in the DePuy nail-bone unit was significantly high compared to the other two nail-bone units and the controls. </span></p><p class="abstract"><strong>Conclusions:</strong> These results question the safety of immediate full weight bearing following surgery when treating the reverse oblique unstable fractures with DePuy intramedullary nails. A period of partial weight bearing following fixation of reverse oblique fractures would be wise when using DePuy nails<span lang="EN-IN">.</span></p>

Proximal Femoral Nail in Reverse Trochanteric Femoral Fractures: An Analysis of 53 Cases at One Year Follow-Up

Treatment of reverse oblique trochanteric femoral fractures poses a lot of challenges. There have been proponents of intramedullary devices as well as extramedullary devices. We present the results of proximal femoral nailing surgery performed for reverse obliquity intertrochanteric fractures using two proximal lag screws and a nail of 250 mm. There is prospective study of fifty three patients with AO/OTA 31 A-A3 fractures being treated by proximal femoral nailing in our institute after seeking approval from the Hospital ethics board. The quality of the reduction, the operative time, complications and the functional status of the patients were the parameters on which the results were evaluated. The mean Harris hip score was 76.66 (range 70 - 93) and the mean Barthel activity score was 16.21 (range 12 - 20). The average surgical time was 50 minutes and the mean consolidation time was 11.5 weeks. Intramedullary nailing with proximal femoral nails seems to be a good option in the treatment of reverse obliquity intertrochanteric fractures as against the various existing options available for the management.

A Comparison of Internal Fixation and Bipolar Hemiarthroplasty for the Treatment of Reverse Oblique Intertrochanteric Femoral Fractures in Elderly Patients.

PurposeTo compare the clinical and radiological results between internal fixation using the proximal femoral nail system and bipolar hemiarthroplasty (BHA) in reverse oblique intertrochanteric hip fractures in elderly patients.Materials and MethodsFrom January 2005 to July 2012, we reviewed the medical records of 53 patients who had been treated surgically for reverse oblique intertrochanteric fracture and had been followed-up on for a minimum of two years. All patients were ≥70 years of age, and divided into two groups for retrospective evaluation. One group was treated with internal fixation using the proximal femoral nail system (31 cases), and the other group was treated with BHA (22 cases).ResultsEarly ambulation postoperatively and less pain at postoperative three month were significantly superior in the BHA group. However, by 24 months postoperatively, the internal fixation group exhibited higher Harris scores and correspondingly less pain than the BHA group. There were no significant differences in union rate, duration of hospitalization or lateral wall fracture healing between the two groups. Four patients in the internal fixation group underwent reoperation.ConclusionIn the treatment of intertrochanteric fracture of the reverse oblique type, open reduction and internal fixation should be considered to be the better choice for patients with good health and bone quality. However, in cases of severe comminition of fracture and poor bone quality, BHA is an alternative offering advantages including early ambulation, less pain at early stages, and a lower risk of reoperation.

English

BACKGROUND: Proximal femoral nail is commonly recommended as treatment of choice for unstable and reverse oblique intertrochanteric fracture in view of superior biomechanics and prevention of varus collapse associated with Dynamic hip screw. Although in stable fracture types DHS is still being preferred as the treatment modality of choice. Proximal femoral nail owing to better biomechanics, less complications can still be used as the method of choice in stable fracture pattern as well. The aim of this study is to evaluate the results of PFN nail in stable intertrochanteric fracture and include evaluation of the mean operative time, amount of blood loss, complications and functional status of the patient. MATERIALS AND METHODS: In this study 30 patients presented to Orthopedics Department Hamidia Hospital Bhopal with stable intertrochanteric fracture were treated with proximal femoral nail. All patients were followed up for a period of 1 year and functional outcome assessment including amount of shortening, neck-shaft angle, Harris hip score was noted. RESULTS: At the time of final follow-up, all 30 patients showed union with average Harris hip score of 86.6 (range 62-94).14 patients had excellent score, 9 patients had good score, 5 patients had fair score and 2 patients had poor outcome. Mean neck shaft angle achieved post-reduction was 131.4 degrees and at final follow-up was 128.4 degrees. Limb length discrepancy was assessed in the final follow-up with average shortening of 5 mm and 4 patients had shortening above 1.5 cm. Average blood loss was 80 ml, the mean operative time was 65 minutes. Complications were seen in 3 cases with one case of local wound infection, one of screw cut-out and one of screw penetration. CONCLUSION: With proper technique PFN gives excellent results with less blood loss and shorter incision with less soft tissue trauma are added advantages which ultimately lead to less morbidity and early mobilisation of the patient and early return to normal routine activities. Most of the complications can be avoided by proper placement of the screw and maintaining proper neck-shaft

Biomechanical outcome of proximal femoral nail antirotation is superior to proximal femoral locking compression plate for reverse oblique intertrochanteric fractures: a biomechanical study of intertrochanteric fractures.

Reverse obliquity intertrochanteric fractures are a challenge for orthopedic surgeons. The optimal internal fixation for repairing this type of unstable intertrochanteric fractures remains controversial. This study aimed to compare the biomechanical properties in axial load and cyclical axial load of proximal femoral nail antirotation (PFNA) and proximal femoral locking compression plate (PFLCP) for fixation of reverse obliquity intertrochanteric fractures. Sixteen embalmed cadaver femurs were sawed to simulate reverse obliquity intertrochanteric fracture and instrumented with PFNA or PFLCP. Axial loads and axial cyclic loads were applied to the femoral head by an Instron tester. If the implant-femur constructs did not fail, axial failure load was added to the remaining implant-femur constructs. Mean axial stiffness for PFNA was 21.10% greater than that of PFLCP. Cyclic axial loading caused significantly less (p=0.022) mean irreversible deformation in PFNA (3.43 mm) than in PFLCP (4.34 mm). Significantly less (p=0.002) mean total deformation was detected in PFNA (6.16 mm) than in PFLCP (8.67 mm). For fixing reverse obliquity intertrochanteric fractures, PFNA is superior to PFLCP under axial load.

Unstable pertrochanteric femoral fractures.

Fractures in the trochanteric region of the femur are classified as AO/OTA 31-A, as they are extracapsular (). This report analyzes the relatively rare 31-A3 fracture, which has also been referred to as an "intertrochanteric femur fracture with subtrochanteric extension," "reverse obliquity intertrochanteric femur fracture," "unstable intertrochanteric femur fracture," or a "subtrochanteric femur fracture." The A3 fracture is characterized by having a fracture line exiting the lateral femoral cortex distal to the vastus ridge. Possible fixation constructs include compression hip screws, intramedullary hip screws, trochanteric intramedullary nails, cephalomedullary antegrade intramedullary nails, and 95° plates. Most reports investigating 31-A fractures do not describe the 31-A3 fracture. For this analysis, only reports clearly indicating that the fracture treated was a 31-A3 were included. It should be understood that this approach therefore excludes reports on generic "subtrochanteric fractures" or "intertrochanteric fractures," some of which may have been 31-A3 fractures. To determine the effect of fixation technique for the AO/OTA 31-A3 fracture on rates of union, infection, risk of reoperation, and functional outcomes.

The Character of Reverse Obliquity Intertrochanteric Fractures in Elderly Patients

Purpose: To discriminate the characteristics between reverse obliquity fractures in the elderly and that of young adults using three-dimensional computed tomography (3D CT). Materials and Methods: Eighteen patients who had reverse obliquity intertrochanteric fractures were enrolled from January 2007 to March 2012. The fracture pattern was analyzed using the 3D CT. The area showing low density (bone defect) of trochanter and femoral neck region was measured. Patients were divided into two groups: Group I, less than 65 years old and Group 2, 65 years and over. Results: In all 9 cases of group 1, the proximal fragment had a ‘V’ shape with an average of 5.6 cm below the vastus ridge; however, the fracture of 8 cases (88.97%) in group 2 had a ‘Λ’ shape of the distal fragment at the level of vastus ridge and an additional fracture line extending to the greater trochanter tip. The bone defect volume of the trochanter and femoral neck region was larger significantly in group 2 than in group 1. Conclusion: Reverse obliquity intertrochanteric fracture in the elderly demonstrated a pattern of bursting fracture with 4 parts, which had different patterns from that of young patients. We believe that the larger volume of bone defects resulted in the difference of fracture patterns between the two groups.

A Comparison of Intramedullary and Extramedullary Fixations for the Treatment of Reverse Oblique or Transverse Intertrochanteric Femoral Fractures

Purpose: This study was designed to compare the clinical and radiological results of intramedullary fixation to those of extramedullary fixation in patients with reverse oblique or transverse intertrochanteric femoral fractures. Materials and Methods: We retrospectively reviewed 39 cases of reverse oblique or transverse intertrochanteric femoral fractures between September 2001 and December 2010. There were 20 cases treated with intramedullary fixation (Group I) and 19 cases treated with extramedullary fixation (Group II). The operative time, intraoperative blood loss, amount of blood transfused, hospital day, and time to bone union were compared between the two groups. Radiologically, the position and sliding length of the lag screw or blade, change of femoral neck-shaft angle, and medialization of distal fragment were compared. Also, complications were assessed. Results: The mean operative time was 87.8 minutes with Group I and 153.8 minutes with Group II. The mean intraoperative blood loss was 375.0 ml with Group I and 1,015.8 ml with Group II. The mean amount of transfusion was 555.5 ml with Group I and 801.6 ml with Group II. The mean time to bone union was 12.1 weeks with Group I and 18.1 weeks with Group II. There were no statistical differences in other parameters between the two groups. Conclusion: The intramedullary fixation group revealed better results in the aspects of invasiveness and time to bone union in comparison with the extramedullary fixation group for the treatment of reverse oblique or transverse intertrochanteric femoral fractures.

Expandable proximal femoral nails versus 95° dynamic condylar screw-plates for the treatment of reverse oblique intertrochanteric fractures

The treatment of a simple (AO/OTA classification 31A3.1) reverse oblique intertrochanteric hip fracture is a challenge for the orthopaedic surgeon. The surgical options include the use of side plates with various angled leg screws or intramedullary devices. The purpose of this study was to retrospectively assess our results of treating reverse oblique fracture with an expendable proximal femoral nail (EPFN) or with a dynamic condylar screw-plate (DCS: 95°) between January 2006 and July 2009. Thirty-three patients (6 males and 27 females, mean age 78 years) met the study inclusion criteria and comprised the two study groups: 19 had been treated by EPFNs and 14 had received DCSs. They were followed for a mean of 28 months (range 6–47). Eight patients (5 EPFN and 3 DCS) died during the follow-up period from causes not related to the operation. Two ESPN patients and 5 DCS patients had malunions. Functional outcome scores showed better results in the EPFN group, but the difference was statistically significant only for the sitting subcategory (p=0.04). Based on our results and experience, we propose that the EPFN is at least as good as the DCS for treating reverse oblique fractures of the femur.

Treatment of comminuted reverse obliquity intertrochanteric fractures using Japanese PFNA

Treatment of comminuted reverse obliquity intertrochanteric fractures using Japanese PFNA

Reverse oblique intertrochanteric femoral fractures treated with the intramedullary hip screw (IMHS)

Recent studies have recommended the use of cephalo-medullary devices for the treatment of reverse oblique intertrochanteric femoral fractures (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen, OTA/AO 31-A3). Both the proximal femoral nail (PFN) and the gamma nail (GN) have shown good outcome results but the results of treatment with the intramedullary hip screw (IMHS) have not been reported in the literature. Our aim was to review the outcomes of these unstable fractures treated with the IMHS implant at our institute. Between 1999 and 2008, 6724 consecutive hip fractures were treated at our institute. There were 115 reverse oblique intertrochanteric fractures and 63 of these were treated with the IMHS. We retrospectively reviewed clinical and radiological records for these fractures treated with the IMHS. Follow-up duration ranged from 1 to 6 years. Amongst the 63 patients treated with the IMHS, 57 (90.5%) fractures were reduced satisfactorily with one poorly positioned hip screw and one breach of the anterior femoral cortex. The mean operative time was 115 min, 22 patients required a blood transfusion and 20 had postoperative medical complications. The major orthopaedic complications included two cases of malrotation, three nonunions and one traumatic periprosthetic fracture with a total failure rate of 7.9%. There were four cases of distal locking bolts breaking or backing out. The 30-day mortality was 6.5%. The clinical and radiological outcomes achieved with the IMHS compare favourably to the results achieved with other cephalo-medullary devices. We consider the long IMHS a good implant for the treatment of these unstable fractures.

Reverse oblique intertrochanteric femoral fractures treated with the Intramedullary Hip Screw (IMHS)

Aims: Reverse oblique intertrochanteric fractures (OTA/ AO 31-A3) have unique biomechanical properties that confer difficulties in obtaining stable fixation with the conventional sliding dynamic condylar screw. Recent studies have recommended the use of cephalocondylic intramedullary devices for these unstable fractures. Both the Proximal Femoral Nail (PFN) and the Gamma Nail (GN) have shown good outcome results but the results of treatment with the IMHS have not been reported in the literature. Methods: Between 1999–2008 6724 consecutive hip fractures were treated at our institute. There were 2586 extracapsular fractures and 307 subtrochanteric fractures. 115 of the extracapsular fractures had a reverse oblique pattern and 63 of these were treated with the IMHS. We retrospectively reviewed clinical and radiological records for the reverse oblique intertrochanteric fractures treated with the IMHS. Follow-up duration ranged from 8 months to 6 years. Results: Among the 63 patients treated with the IMHS, 56 (88%) fractures were reduced satisfactorily with only one poorly positioned hip screw in the femoral head. There were no cases of femoral shaft fracture, screw cut-out or collapse at the fracture site. The orthopaedic complications were two cases of mal-rotation, two cases of non-union, two cases of distal locking bolts backing out, and one cracked nail. 30 day mortality was 6.5%. Conclusion: Cephalo-medullary nailing devices have been recommended for the treatment of reverse oblique intertrochanteric femoral fractures. Our clinical and radiological outcomes with the IMHS compare favourably to the results in reports where other cephalo-medullary devices have been used. Therefore we consider the IMHS a good option for the treatment of these unstable fractures.

Treatment of reverse oblique trochanteric femoral fractures with proximal femoral nail

Treatment of reverse oblique trochanteric femoral fractures is still challenging. We present the results of our proximal nailing surgery performed for reverse obliquity intertrochanteric fractures using two lag screws and evaluated the quality of the reduction, operative time, complications and functional status of the patients. Fifteen patients with AO/OTA 31 A-A3 fractures were treated by proximal femoral nailing in our trauma centre. The mean Harris hip score was 74.66 (range 65-96) and the mean Barthel activity score was 15.71 (range 12-20). The mean duration of surgery was 48 minutes and the average consolidation time was 8.6 weeks. No intraoperative complications or postoperative technical failures and no stress shielding as evidenced by the lack of cortical hypertrophy at the level of the tip of the implant were detected. Intramedullary nailing with proximal femoral nails may be a good option in the treatment of reverse obliquity intertrochanteric fractures.

Biomechanical Evaluation of Extramedullary Versus Intramedullary Fixation for Reverse Obliquity Intertrochanteric Fractures

This study evaluated the 135-degree hip screw, 95-degree hip screw, and intramedullary hip screw (IMHS) for fixation of reverse obliquity intertrochanteric fractures. Twelve matched pairs of human femora (mean age 64 years) were obtained. Osteotomies were created in left femurs at a 33-degree angle, running inferolaterally from the lesser trochanter to mimic reverse obliquity intertrochanteric fractures. Right femora acted as controls. Three groups of left femora (n = 4 per group) had a 135-degree hip screw, 95-degree hip screw, or IMHS inserted. Strain gages were placed distal to the fracture site to monitor fragment strain. A linearly variable differential transformer measured lateral displacement of the proximal femur. An Instron tester applied vertical loads to the femoral head. Outcome measures of stiffness, strain, and lateral displacement were determined at 25-degree adduction, 25-degree abduction, 25-degree flexion, and 90-degree flexion. A 2-cm bone gap was then created at the fracture site to simulate comminution and the mechanical tests repeated. Failure load was assessed in 25-degree adduction with a bone gap. There was no difference in normalized stiffness between constructs before creation of a gap. After gap creation, stiffness of all constructs was reduced (P = 0.03), and there was a significant difference in adduction (135-degree hip screw, 46.6% +/- 3%; 95-degree hip screw, 22.9% +/- 2%; and IMHS, 53.7% +/- 7.8%) (P < 0.05). Similar results were noted for abduction and flexion. There was no significant difference in lateral displacement between constructs before (P = 0.92) or after (P = 0.26) gap creation. Failure load was significantly different (135-degree hip screw, 1222 +/- 560 N; 95-degree hip screw, 2566 +/- 283 N; and IMHS, 4644 +/- 518 N) (P = 0.02). With bone contact, there were no statistically significant differences in the stiffness between the constructs. With a gap, however, the IMHS bone implant construct was significantly stiffer and had a greater load to failure than the 135-degree and 95-degree constructs.

The Treatment of Reverse Obliquity Intertrochanteric Fractures With the Intramedullary Hip Nail

Reverse obliquity intertrochanteric fractures have been recognized as having unique anatomic and mechanical characteristics. Even though some clinical reports regarding intramedullary hip nailing for reverse obliquity intertrochanteric fracture show favorable results, there has been no clinical report of intramedullary hip nailing regarding the clinical significance of the lesser trochanteric fragment which differentiates Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 31-A3.3 from A3.1 and A3.2. We retrospectively reviewed the clinical results of 46 cases of reverse obliquity or transverse intertrochanteric fracture treated with intramedullary hip nails. Twenty-five fractures were fixed with proximal femoral nail (PFN), and 21 fractures were fixed with intertrochanteric subtrochanteric nail. Among 40 patients, followed up for more than 6 months, 22 31-A3.3 fractures (84.6%) out of 26 and all 14 A3.1 or A3.2 fractures were healed after the first operation. The complications were four cases of fixation failure and one case of femoral shaft fracture after fall. They occurred in the A3.3 type fracture, which were fixed with the PFN. The mean union time was longer in the A3.3 group (5.98 months, range 3-17 months) compared with that in the A3.1 or A3.2 group (4.65 months, range 3-9 months) (p = 0.048). Two cases of reciprocal migration of two screws (Z-effect) required exchange of the femoral neck screw to a shorter one in the PFN group. The amount of sliding of the femoral neck screw of the PFN (6.8 mm, range 0.3 mm-16.5 mm) was greater than that of the intertrochanteric subtrochanteric nail lag screw (1.89 mm, range: 0.2 mm-4.6 mm) (p = 0.012). Statistical analysis showed that the type of implant PFN, fracture subtype (31-A3.3), and old ages (more than 65 years old) significantly prolonged the union time (p < 0.05). The lesser trochanteric fragment and posteromedial defect in 31-A3.3 fracture seems to play an important role in the stability after intramedullary hip nailing. The causes of fixation failure in the PFN group were associated with excessive sliding of femoral neck screw, which was aggravated by toggling motion in the 31-A3.3 fractures.

Proximal Femoral Nail for the Treatment of Reverse Obliquity Intertrochanteric Fractures Compared With Gamma Nail

The reverse obliquity fracture of the proximal femur (AO/OTA 31-A3) is mechanically different from most intertrochanteric fractures. The purpose of this study was to compare the results of proximal femoral nail (PFN) fixation with those of gamma nail (GN) fixation for these fractures. Between 1993 and 2003, 635 of the fractures were classified as intertrochanteric or subtrochanteric. Clinical and radiographic records were retrospectively reviewed, and 22 fractures with reverse obliquity pattern were identified. The patients were divided into two treatment groups and were followed up for a minimum of 1 year (range, 12-67 months). Eleven patients in group I were treated with the PFN, and 11 patients in group II were treated with the GN. The two groups were comparable with regard to demographic and injury variables. The duration of follow-up averaged 18 months (range, 12-67 months). Radiographic changes during the follow-up, clinical outcome, and complications of the PFN group were compared with those of the GN group. Reverse obliquity intertrochanteric fractures accounted for 4.3% of intertrochanteric and subtrochanteric fractures. Bone union time averaged 16.5 weeks in the PFN group and 17.9 weeks in the GN group. Average sliding of lag screw was 2.5 mm in the PFN group and 3.1 mm in the GN group (p = 0.046). Change of the neck-shaft angle was 2.45 degrees in the PFN group and 3.75 degrees in the GN group (p = 0.032). A satisfactory functional outcome was found in eight patients in the PFN group and also in eight patients in the GN group. There was one osteonecrosis of femoral head in the PFN group. There was one cutting out of lag screw, one nonunion, and one varus deformity in the GN group. There was no difference in clinical outcome between the PFN and GN groups. However, the PFN demonstrated better results biomechanically than the GN did in terms of less sliding of lag screw, less change of neck-shaft angle, and less complications for the treatment of reverse obliquity intertrochanteric fractures.

Reverse oblique intertrochanteric femoral fractures treated with the gamma nail.

We studied 47 reverse oblique intertrochanteric femoral fractures that were treated with gamma nails between 1992 and 2000. Fracture reduction was satisfactory in 38 patients (81%), the hip screw position was correct in 42 (89%) and there were no peri-operative complications. However, in three patients the nail displaced, resulting in non-union in one and protrusion into the acetabulum in another. A logistical regression analysis of our series showed that an incorrect position of the hip screw in the femoral head was the only predictor for complications. Thus, we consider that the gamma nail is a good option for the treatment of these complex fractures.

Unstable Pertrochanteric Femoral Fractures

Fractures in the trochanteric region of the femur are classified as AO/OTA 31-A, as they are extracapsular. This report analyzes the relatively rare 31-A3 fracture, which has also been referred to as an "intertrochanteric femur fracture with subtrochanteric extension," "reverse obliquity intertrochanteric femur fracture," "unstable intertrochanteric femur fracture," or a "subtrochanteric femur fracture." The A3 fracture is characterized by having a fracture line exiting the lateral femoral cortex distal to the vastus ridge. Possible fixation constructs include compression hip screws, intramedullary hip screws, trochanteric intramedullary nails, cephalomedullary antegrade intramedullary nails, and 95 degrees plates. Most reports investigating 31-A fractures do not describe the 31-A3 fracture. For this analysis, only reports clearly indicating that the fracture treated was a 31-A3 were included. It should be understood that this approach therefore excludes reports on generic "subtrochanteric fractures" or "intertrochanteric fractures," some of which may have been 31-A3 fractures. To determine the effect of fixation technique for the AO/OTA 31-A3 fracture on rates of union, infection, risk of reoperation, and functional outcomes.

The Treatment of Unstable Reverse Oblique Intertrochanteric Fractures with Proximal Femoral Nail (PFN)

Purpose: To investigate the results of treatment of unstable reverse oblique intertrochanteric fractures with proximal femoral nail (PFN). Materials and Methods: We reviewed the results of 16 cases of AO 31-A3.3 intertrochanteric fracture treated with PFN from September 2000 to February 2004 which could be followed up for more than six months and untill bone union. The mean age was 60.2 years old. We investigated the union time and amount of sliding of two screws (neck screw and anti-rotational hip pin) and complications such as fixation failure and nonunion. Functional results were evaluated by the Parker and Palmer mobility score and Jensen social-function score. Results: All fractures were united and the mean union time were 6.9 months. The amount of sliding of the neck screws and anti-rotational hip pin was 4.8 mm and 3.8 mm on average in 14 cases, respectively. Fixation failure and excessive migration of the screws occurred in two cases; One case showed so-called Z-effect of two screws (reciprocal movement of two screws) and nonunion. The other case showed proximal migration and cutout of the neck screw. There was one femoral shaft fracture at the nail tip caused by a slip. Eight cases (50%) and eleven cases (68.8%) were fully recovered according to Parker and Palmer mobility score and Jensen social-function score, respectively. Conclusion: We consider that PFN is a suitable implant for treatment of unstable reverse oblique intertrochanteric fractures. However, the revision of implant design is recommended to prevent the excessive migration of the femoral neck screw and anti-rotational hip pin.

Dynamic hip screw in the management of reverse obliquity intertrochanteric neck of femur fractures

Aim: To assess the results of treatment of reverse obliquity intertrochanteric fractures at Middlemore hospital and to compare this to the results in the literature. Method: This was a retrospective review of X-rays and clinical notes followed by phone conversations with the patients. Results: Forty-two patients with reverse obliquity intertrochanteric neck of femur fractures were included. They were treated with one of three different implants (dynamic hip screw (DHS), reconstruction nail (RCN) or proximal femoral nail (PFN)). The revision rate for the DHS was 11% (4/35), RCN 40% (2/5) and PFN 0% (0/2). Of the 35 DHS implants, one was below a hip fusion. Of the remaining 34, 25 had the screws placed within 25 mm of the subchondral bone at the centre of the femoral head and nine did not. None of the implants placed within 25 mm of the femoral head failed while three of the others did. Conclusion: The results for treating this type of fracture with the DHS in this series are significantly better than that documented in the literature for the same fracture type, the reasons for this are unclear. There seems to be a trend towards better results with more accurate placement of the lag screw with this device. In this series, the RCN was less successful than the DHS and the PFN was used too infrequently to draw useful conclusions about its effectiveness.