Purpose: To report long-term results (with a minimum follow-up of 13 years) of GR construct [Luque-trolley (LT)] in EOS, to identify factors predictive of curve progression and to establish the timing of definitive fusion.

Method: The study cohort consisted of 37 patients (22M & 15F) who had primary LT between 1983–1995 were reviewed. Group I: 7 patients had LT alone and Group II: 30 had LT with convex fusion. Cobb at initial presentation, after first surgery, before definitive fusion and at the latest follow-up was recorded. Other radiological curve parameters recorded were rib spinal angle difference (RSAD), end vertebral tilts (EVT), apical vertebral rotation (AVR) and T1-S1 length. Complications with respect to development of junctional/apical kyphosis, implant failure, pseudoarthrosis (PA), sagittal/coronal profile and instrumented spinal segment growth at maturity were evaluated.

Results: The mean age at definitive fusion for study cohort was 12.5 years. Group I: Mean age at first surgery was 7.4 years (3.3–9.5y). Mean pre-op Cobb angle of primary curve was 600 (310–710) which was corrected to 280 (200–360). They underwent definitive segmental spinal instrumentation(SSI) with fusion at 13.9 years (9.8–15.1y) when the curve had worsened to 480 (400–650). Group II: Mean age at index surgery was 3.6 years (1.6–8.8y). Mean pre-op Cobb of primary curve was 580 (300–900) which corrected to 300 (100–620). 16/30 patients underwent definitive SSI with fusion at 11.5 years (8.5–14.2y) when the curve deteriorated to 600 (530–770). Instrumented segmental spinal growth was 3.2cms (SD±1.45; range 1–5cms). 14/30 maintained their correction till skeletal maturity. JK was observed in 8 cases [proximal(3), distal(2) & apical(3)] which were corrected at the time of definitive SSI. There was a linear relationship between Cobb angle at definitive fusion with concaveRSA and upperEVT.

Conclusion: Correlation and regression statistics revealed predictive factors of curve progression to be concave RSA (®=0.91 & p=0.001) and upper EVT (®=0.81 & p=0.0004). Patients with high concave RSA and upper EVT should be closely monitored for deterioration. Spinal growth that exceeds the capacity of LT to elongate leads to apical kyphosis. Timing of definitive fusion is influenced by growth velocity, clinico-radiological factors and complications.

Purpose: Intra-op localisation of small nidus in Osteiod osteoma and Osteoblastomas is often difficult resulting in failed excision with persistent pain. We report two year follow-up results of the efficacy and reliability of using an intra-operative gamma probe in conjunction with fluoros-copy to aid resection in primary and revision surgeries.

Method: Eight patients (6M; 2F) with a diagnosis of osteoid osteoma (7) and osteoblastoma (1) were seen at our centre. The mean age at presentation was 20.9 years (9–31y). The tumour was localised to cervical (2), thoracic(4) and lumbar (2) posterior elements. All had back or neck pain of varying duration with a mean of 20 months (6–48mo). Three patients had failed treatments including CT-guided radiofrequency ablation in one and surgical excision under fluoroscopy in two. No case had previously utilised an intra-op gamma probe for localisation. All patients had work-up with plain X-rays, CT, MRI and 99 m Technetium bone scan to identify and localise the lesion. A pre-requisite for use of intra-op gamma probe was a positive pre-op bone scan. On the day of surgery, 600 MBq Tech HMDP (hydroxy-methylene-di-phosphate) was administered IV 3 hours prior to surgery. Fluoroscopy was used to confirm anatomical level, permanent mark made on skin and area exposed surgically. A 5 mm cadmium telluride (Cd Te) probe (which converts gamma radiation into electrical signal) and rate meter were used to scan the area containing lesion and counts per second(cps) recorded. The tumour nidus was then excised and cps from tumour bed and excised specimen recorded.

Results: The mean follow-up was 5.85 years (2–12.3y). The mean cps for osteoid osteoma pre-excision was 203.8 (60–515), which fell to 72.5 (10–220) post-excision. The cps reduced from 373 to 40.5 post-operatively for Osteoblastoma. Complete excision was recorded every time and all patients reported characteristic disappearance of pre-operative pain. All had discontinued analgesic medication and returned to normal activity by three months. All patients were followed-up regularly when they filled NDI, ODI and SF-36.

Conclusion: Gamma probe guided surgical excision facilitates accurate localisation of lesion, is less invasive and most importantly confirmation of complete excision of the tumour nidus consistently every time.

There is no data concerning morphological dimensions of distal femur, proximal tibia and patella in Indian population. The objective was to analyse the anthropometric data in Indian knees and to co-relate them with existing knee arthroplasty systems.

MRI scans of 25 patients (15 males & 10 females) who underwent bilateral knee scans for ligamental injuries were collected. Patients with arthritis, bone loss, varus/valgus deformity of > 15 degrees and those with immature skeleton were excluded.

The mean age was 32 yrs (18–53 yrs). Three surgeons independently measured medio-lateral (ML), antero-posterior(AP) dimensions & aspect ratio(AR) of distal femur, proximal tibia and unresected patellar thickness(PT) on three occasions one week apart to account for intra & inter-observer variability. The resultant data of 50 knees was analysed using SPSS v14.0 and compared with five prosthesis knee systems (PFC sigma, NexGen, Scorpio, IB-II & Gender specific knee). The mean ML & AP for proximal tibia was 73.3±5.3 & 47.8±4.3 mm. The mean ML & AP (lateral condyle) for distal femur was 74.3±5.9 & 65.4±5.0 mm. The mean PT was 24.7 & 21.8 mm in males & females respectively. The ML & AP showed a statistically significant positive correlation with the height of the person (ML r=0.55; AP r=0.50 & p=0.01). The tibial and femoral AR showed higher ratio for smaller knees & smaller ratio for larger knees i.e. decline in AR for increasing AP dimension. None of the prosthesis designs mimicked this decrease in AR and NexGen prosthesis infact showed an increase in AR. Gender differences in the morphological data were shown by variable tibial AR.

Most of the available TKR prosthesis designs differ from actual knee morphometry of Indian population. These data provides the basis for designing optimal prosthesis for people of Indian/Asian origin in UK and overseas.