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

Background: 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.Methods: 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.Results: 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. Conclusions: 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

Interbody Fusion in Low Grade Lumbar Spondylolsithesis: Clinical Outcome Does Not Correalte with Slip Reduction and Neural Foraminal Dimension

Study DesignProspective nonrandomized study.PurposeTo find a possible correlation between clinical outcome and extent of lumbar spondylolisthesis reduction.Overview of LiteratureThere is no consensus in the literature concerning whether a beneficial effect of reduction on outcome can be expected following reduction and surgical fusion for low grade lumbar spondylolisthesis.MethodsForty six patients with a mean age of 37.5 years (age, 17–48 years) with isthmic spondylolisthesis underwent interbody fusion with cages with posterior instrumentation (TLIF). Clinical outcome was measured using visual analogue score (VAS) and Oswestry disability index (ODI). Foraminal dimensions and disc heights were measured in standard digital radiographs. These were analyzed at baseline and 1 year after surgery and changes were compared. Radiographic fusion was judged with computed tomography scans at 1 year.ResultsNinety percent of the patients had good or very good clinical results with fusion and instrumentation. Baseline and one-year postoperative mean VAS score was 6.33 (range, 5–8) and 0.76 (range, 0–3), respectively (p=0.004). Baseline and one-year postoperative, mean ODI score was 48 (range, 32–62) and 10 (range, 6–16), respectively (p<0.001). A mean spondylolisthesis slip of 32.1% was reduced to 6.7% at 1 year. Average anterior disc height, posterior disc height, vertical foraminal dimension), and foraminal) diameter improved from 9.8 to 11.7 mm (p=0.005), 4.5 to 5.8 mm (p=0.004), 11.3 to 12.6 mm (p=0.002), and 18.6 to 20.0 mm (p<0.001), respectively. The fusion rate was 75% with TLIF. There is no significant correlation between the improvements of ODI scores and the extent of slip reduction.ConclusionsNeural decompression and interbody fusion can significantly improve pain and disability but the clinical outcome does not correlate with radiological improvement in the neural foraminal dimension

Single-Stage Combined Anterior Corpectomy and Posterior Instrumented Fusion in Tuberculous Spondylitis With Varying Degrees of Neurological Deficit.

BACKGROUND: A combined anterior decompression and stabilization followed by posterior instrumented fusion promotes fusion of the affected segment of spine and prevents further progression of deformity. The objective of this study is to report on outcome of patients with tuberculous spondylitis, progressive neurologic deficit, and kyphotic deformity who underwent single-stage anterior corpectomy and fusion and posterior decompression with instrumented fusion. METHODS: A total of 49 patients (29 males, 20 females) with varying grades of neurological deficit due to tuberculosis of the spine (thoracic, thoracolumbar, and lumbar) were included in this prospective study. The diagnosis of tubercular infection was established after clinical, hematological, radiological, and histological specimens taken at surgery. All were treated with combined anterior and posterior decompression, debridement, and stabilization with direct autologous bone grafting or wrapped bone graft in mesh or expandable cages. Neurological status and visual analog scale (VAS) pain score were recorded at each visit. X-rays, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and liver function were evaluated at 3, 6, and 12 months after surgery and then once a year thereafter. Results were analyzed in terms of neurological recovery (Frankel grade), bony union time, and correction of kyphotic deformity. RESULTS: The mean age was 37.8 years (range, 2-65 years). Mean preoperative VAS scores improved from 5.6 to 1.5. The average ESR and CRP returned to normal within 6 months in all patients. The mean time to fusion was 8.4 months for the whole group. The neurological deficit in 42 of 49 patients had excellent or good clinical outcome ( CONCLUSIONS: Combined single-stage anterior decompression and stabilization followed by posterior instrumented fusion is safe and effective in the treatment of tuberculous spondylitis with neurological deficit in the thoracic and lumbar spine. This procedure helps to correct and maintain the deformity, abscess clearance, spinal-cord decompression, and pain relief as well as return to normal motor function. Bony fusion prevents further progression of deformity. LEVEL OF EVIDENCE: 2

Interbody Fusion in Low Grade Lumbar Spondylolsithesis: Clinical Outcome Does Not Correalte with Slip Reduction and Neural Foraminal Dimension.

STUDY DESIGN: Prospective nonrandomized study. PURPOSE: To find a possible correlation between clinical outcome and extent of lumbar spondylolisthesis reduction. OVERVIEW OF LITERATURE: There is no consensus in the literature concerning whether a beneficial effect of reduction on outcome can be expected following reduction and surgical fusion for low grade lumbar spondylolisthesis. METHODS: Forty six patients with a mean age of 37.5 years (age, 17-48 years) with isthmic spondylolisthesis underwent interbody fusion with cages with posterior instrumentation (TLIF). Clinical outcome was measured using visual analogue score (VAS) and Oswestry disability index (ODI). Foraminal dimensions and disc heights were measured in standard digital radiographs. These were analyzed at baseline and 1 year after surgery and changes were compared. Radiographic fusion was judged with computed tomography scans at 1 year. RESULTS: Ninety percent of the patients had good or very good clinical results with fusion and instrumentation. Baseline and one-year postoperative mean VAS score was 6.33 (range, 5-8) and 0.76 (range, 0-3), respectively (p=0.004). Baseline and one-year postoperative, mean ODI score was 48 (range, 32-62) and 10 (range, 6-16), respectively (p CONCLUSIONS: Neural decompression and interbody fusion can significantly improve pain and disability but the clinical outcome does not correlate with radiological improvement in the neural foraminal dimension

Predictive Factors for the Outcome of Surgical Treatment of Lumbar Spondylolysis in Young Sporting Individuals.

STUDY DESIGN: Retrospective consecutive case series. OBJECTIVES: Only few sporting individuals with symptomatic lumbar pars injuries require surgical repair and it is often difficult to predict the outcome following surgery. The factors that predict the outcome after direct repair of lumbar pars defect was evaluated clinically and statistically. The preoperative background variables both subjective and objective as well as radiological evaluation were used in a multiple regression model to find the strong predictors of postoperative outcome as measured by VAS (visual analogue scores), ODI (Oswestry Disability Index) and SF-36 (Short Form). METHODS: Fifty-two consecutive young sporting individuals with a mean age of 19 years (range 8-30 years) were treated surgically for lumbar pars defect confirmed on imaging studies (ie, single-photon emission computed tomography, computed tomography, and magnetic resonance imaging). Fifty patients completed the VAS, ODI, and SF-36 questionnaires as a part of their assessment. Preoperative background variables were used in a multiple regression model to find the strongest predictor of postoperative outcome as measured by ODI. Ethical approval was taken by the institutional review board. RESULTS: Buck\u27s screw repair of the pars defect was carried out in 44 patients (33 males, 11 female): unilateral in 8 patients (7 males, 1 female) and bilateral in 36 patients (26 males, 10 females). Although age at surgery showed linear colinearity (ρ = 0.32, CONCLUSIONS: The outcome after direct repair of pars defect in those younger than 25 years runs a predictable course. Professionalism in sports has a high impact on the outcome. Preoperative ODI and SF-36 PCS scores are significant predictors of good functional outcome. The regression equation can predict the outcome in 80.9% sporting individuals undergoing Buck\u27s repair

A prospective randomized comparison of coralline hydroxyapatite with autograft in cervical interbody fusion.

STUDY DESIGN: A prospective randomized trial with independent clinical and radiographic outcome review of patients receiving either hydroxyapatite or tricortical iliac crest graft for cervical interbody fusion was conducted. OBJECTIVE: To determine whether coralline-derived hydroxyapatite is a suitable bone graft substitute in cervical interbody fusion. SUMMARY OF BACKGROUND DATA: Tricortical iliac crest bone is the gold standard graft material for cervical interbody fusion. Various bone substitutes have been used for this procedure to avoid potential donor site morbidity. ProOsteon 200 is a coralline-derived hydroxyapatite product, the use of which remains unclear for cervical interbody fusion. METHODS: In this study, 29 patients undergoing anterior cervical fusion and plating were randomized to receive either ProOsteon 200 or iliac crest grafts. The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Postoperative radiographs were analyzed for graft fragmentation, loss of height, angular alignment, and hardware failure to assess structural integrity of the graft material. Plain radiographs and computed tomography scans were used to evaluate fusion. RESULTS: Both the ProOsteon 200 and iliac crest groups demonstrated significant improvement in clinical outcome scores. There was no significant difference in clinical outcome or fusion rates between the two groups. Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (P = 0.001). Significant graft settling occurred in 50% of the hydroxyapatite grafts, as compared with 11% of the autografts (P = 0. 009). One patient in the ProOsteon 200 group required revision surgery for graft failure. CONCLUSIONS: ProOsteon 200 does not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion

Long-term outcome after surgical treatment of Scheuermann\u27s Kyphosis (SK).

STUDY DESIGN: A retrospective observational cohort study with a minimum follow-up of 10 years of patients who underwent surgery for Scheurmann Kyphosis (SK). OBJECTIVE: Evaluate the long-term clinical and radiological outcome of patients with SK who either underwent combined anterior-posterior surgery or posterior instrumented fusion alone. There is paucity of literature for long-term outcome studies on SK. The current trend is towards only posterior (PSF) surgical correction for SK. The combined strategy of anterior release, fusion and posterior spinal fusion (AF/PSF) for kyphosis correction has become historic relic. Long-term outcome studies comparing the two procedures are lacking in literature. METHODS: 51 patients (30 M: 21F) who underwent surgery for SK at a single centre were reviewed. Nineteen had posterior instrumentation alone (PSF) (Group 1) and 32 underwent combined anterior release, fusion with posterior instrumentation (AF/PSF) (Group 2). The clinical data included age at surgery, gender, flexibility of spine, instrumented spinal levels, use of cages and morcellised rib grafts (in cases where anterior release was done), posterior osteotomies and instrumentation, complications and indications for revision surgery. Preoperative flexibility was determined by hyperextension radiographs. The radiological indices were evaluated in the pre-operative, 2-year post-operative and final follow-up [Thoracic Kyphosis (TK), Lumbar lordosis (LL), Voustinas index (VI), Sacral inclination (SI) and Sagittal vertical axis (SVA)]. The loss of correction and incidence of JK (Junctional Kyphosis) and its relation to fusion levels were assessed. Complications and difference in outcome between the two groups were analyzed. RESULTS: The mean age at surgery for 51 patients was 20.6 years who were followed up for a minimum of 10 years (mean: 14 years; range 10-16 years). The mean age was 18.5 ± 2.2 years and 21.9 ± 4.8 years in groups 1 and 2, respectively. The mean pre- and 2-year post-operative ODIs were 32.6 ± 12.8 and 8.4 ± 5.4, respectively, in group 1 (p \u3c 0.0001) and 30.7 ± 11.7 and 6.4 ± 5.7, respectively, in group 2 (p \u3c 0.0001). The final SRS-22 scores in group 1 and 2 were 4.1 ± 0.4 and 4.0 ± 0.35, respectively (p = 0.88). The preoperative flexibility index was 49.2 ± 4.2 and 43 ± 5.6 in groups 1 and 2, respectively (p \u3c 0.0001). The mean TKs were 81.4° ± 3.8° and 86.1° ± 6.0° for groups 1 and 2, respectively, which corrected to 45.1° ± 2.6° and 47.3° ± 4.8°, respectively, at final follow-up (p \u3c 0.0001). The mean pre-operative LL angle was 60.0° ± 5.0° and 62.4° ± 7.6° in groups 1 and 2, respectively, which at final follow-up was 45.1° ± 4.4° and 48.1° ± 4.8°, respectively (p \u3c 0.0001). The mean pre-operative and final follow-up Voustinas index (VI) in group 1 were 22.9 ± 2.9 and 11.2 ± 1.2, respectively, and in group 2 was 25.9 ± 3.5 and 14.0 ± 2.3, respectively. The mean pre-operative and final follow-up SI angle were 43.6° ± 3.3° and 31.2° ± 2.5° in group 1, respectively, and 44.3° ± 3.5° and 32.1° ± 3.5° in group 2, respectively (p \u3c 0.0001). The pre-operative and final follow-up SVA in group 1 were - 3.3 ± 1.0 cms and - 1.3 ± 0.5 cms, respectively, and in group 2 was - 4.0 ± 1.3cms and - 1.9 ± 1.1cms, respectively (p \u3c 0.0001). Though the magnitude of curve correction in the groups 1 and 2 was significant 36° vs 39° (p = 0.05), there was no significant difference in correction between the two groups. Proximal JK was seen in seven and distal JK in five patients were observed in the whole cohort. CONCLUSION: The long-term clinical outcomes for both PSF and AF/PSF are comparable with reproducible results. No difference was noted in loss of correction and outcome scores between the two groups. The correction of thoracic kyphosis (TK) had a good correlation with ODI. AF/PSF had much higher complications than PSF group. The objective of correcting the sagittal profile and balancing the whole spinal segment on the pelvis can be achieved through single posterior approach with fewer complications