For many surgeons amputation is the usual treatment in sarcoma of the foot. The aim of our study was to report the functional and oncologic results of treatment in 54 sarcomas of the foot to assess if conservative treatment was acceptable

We retrospectively reviewed the records of 54 patients with sarcomas of the foot, aged 6 to 50 (mean 17), 30 females and 26 males. At time of referral, 18 had a local recurrence of a previous inadequate treatment. There were 27 soft tissue sarcomas (STS: 10 synovial sarcomas, 6 rhadomyosarcomas, 1 liposarcomas and 10 others) and 27 bone tumours (16 Ewing's, 8 chondrosarcomas, 3 osteosarcomas). Toes tumours were excluded, 18 tumours involved the metatarsal, 12 the plantar soft tissues, 11 the calcaneum, 3 the talus, 2 the midtarsal bones.

Surgery consisted in 19 resection without reconstruction, 21 resections with bone reconstruction, 9 partial amputations of the foot, and 6 trans tibial amputations.

In 34 cases surgical margins were adequate (R0), in 13 patients resection was inadequate (9 R1 and 4 R2). In 7 cases the margins were not assessed.

After a 5.5 years average follow-up (3m to 17y), 31 patients had no evidence of disease, 8 were in second remission, 4 had an evolutive disease and 11 were deceased. The mean MSTS score was 26/30 (31 cases).

In conclusion, a conservative treatment is feasible in metatarsal bones with skin coverage by flap if necessary. In STS adequate margins are difficult to achieve with a high rate of local recurrence. In calcaneus and talus, a conservative treatment is possible in tumours limited to bone after good response to chemotherapy. In other cases conservative treatment is debatable because amputation gives excellent functional results.

Expandable prostheses were designed to allow progressive growth after tumour resection in children. The aim of this study was to report the late results of the non-invasive growing prostheses designed by A Soubeyran (Phenix prosthesis or Wright Repiphysis).

From 1994 to January 2006, 27 children aged 4 to 12 (mean 8.5), underwent a resection of the knee for a bone tumour, with reconstruction by a non invasive expandable prosthesis. There were 16 boys and 11 girls. The tumours were 25 osteosarcomas and 2 Ewing tumours. All patients received pre and post-operative chemotherapy. There were 18 distal femur, 7 proximal tibia, and 2 femur + tibia resections.

There were different successive designs based on the same electro-magnetic growing mechanism using a pre bent spring, released by eating in an induction coil.

After, 7.2 years mean follow-up (4 months to 15 years), 20 patients had no evidence of disease and 7 were deceased. Two with a local recurrence were amputated. Mean lengthening was 5.1 centimeters (0 to 8), after 3 to 11 lengthening procedures. Mean limb-length discrepancy was 1.8 cm. Two patients had a secondary infection. Eleven had a revision for arthrofibrosis. All surviving patients were revised to a conventional hinged prosthesis. The mean MSTS functional score of the definitive prosthesis was 82% (63 to 96%).

Theses prostheses showed many mechanical complications as loosening, fracture of the growing mechanism, and arthrofibrosis. The positive outcome was the possibility to perform a progressive lengthening, without surgery limiting the risk of infection. Theses prostheses should be considered as temporary until reconstruction with a conventional hinged prosthesis. Patients with multiple revisions had a tendency to show less favourable late functional results than with primary implanted hinged prosthesis.

Purpose of the study: The purpose of this work was to study outcome at the end of grow after surgical treatment for idiopathic congenital equinovarus club foot.

Material and methods: From 1983 to 1991, 63 children (85 club feet) given functional treatment underwent surgery because of insufficient results. At birth, the Dimeglio classification was II:11.7%; III:40%; IV:25.8%. Surgery was performed before the age of 2 years for 52 fee (61%) and after 2 years for 33. The indication for surgery was a triple deformity: equin (8.1±15.2, varus (8.2±13.1, adductus (32.5±13.8). Surgery was associated as needed with posterolateral release (94.1%), anteromedial release (92.9%), plantar release (61.1%) and Lichtblau shortening of the lateral column (42%). The tendon of the tibialis anterior was lengthened for 86% of the feet. Functional, clinical, and radiographic outcomes were noted at last follow-up.

Results: Mean follow-up was 15 years (8–22). Fifteen feet (17.6%) had a second operation: 13 for recurrence (repeat release), one for over correction (lengthening of the calcaneum) and one for metatarsus adductus (metatarsal osteotomies). One foot had a third operation for recurrence (repeat release). Three feet (3.5%) did not have surgery; a double arthrodesis followed progressive aggravation during growth. In the first group (surgery before 2 years), outcome was very good, good or fair for 76.9, 17.3 and 5.8% of the feet. The “fair” outcomes concerned three children who had more than one operation. In the second group (surgery after 2 years), the outcomes were 78.8%, 18.2% and 3% (n=1) respectively. The “fair” result concerned the double arthrodesis. There was no significant difference for the final outcome as a regards age at surgery (p=0.07). Among the four feet with a “fair” outcome, two were initially Dimeglio III and two Dimeglio IV.

Discussion: Soft tissue release enables correct results at the end of growth for the majority of these club feet. While the Dimeglio score is an element predictive of an indication for surgery, it is not a prognostic element for the final outcome. Age at surgery does not have a significant impact on the final outcome.

Purpose of the study: The anatomic, clinical and radiographic expression of congenital genu recurvatum corresponds to femorotibial subluxation. The clinical presentation can vary, ranging from an easily reducible subluxation to irreducible dislocation.

Material and methods: Fifty five patients (82 knees) were treated, mean age 2 days. Genu recurvatum was isolated (n=15 children), associated with hip dislocation or foot deformity (n=40 children), arthrogyrposis (n=10 children, or Larsen syndrome (n=3 patients). Were studied: anterior skin folds, anteroposterior femorotibial instability, joint range of motion at first exam and last follow-up. The Seringe classification was noted at birth: I – reducible (n=59 knees), II – difficult to reduce (n=12 knees), III – irreducible (n=11 knees). Mean follow-up was 4 years, 13 years, and 9 years for class I, II and III knees respectively. Orthopaedic treatment was performed in all cases with manipulations, braces, traction and plaster cast for at least 40 days. In the event of failure, a V/Y lengthening of the quadriceps was performed, associated with joint release.

Results: At the first exam, the skin folds were present in all cases in group I, 2/3 in group II, and absent in group III. Mean maximal flexion was 66, 43 and 17 respectively in groups I, II and III. The even operated knees were in group III. At last follow-up, the mean maximal flexion was 146, 124 and 77 respectively in groups I, II and III. Six knees presented anteroposterior instability in groups I, 3 in group II and 3 in group III. In group I, the final clinical outcome was good or very good in 55 knees (93%), fair in 4. In group II, good or very good outcome was noted in 8 knees (67%), fair in 3 (25%), and poor in 1 knee. In group III, outcome was faire in 4 (36%) and poor in 7 (64%). In this group, poor outcome corresponded to 86% of the operated knees.

Discussion: At the first exam, factors having the most unfavourable impact were: absence of an anterior skin fold, knee flexion < 50, irreducible femorotibial dislocation, and syndrome context. We emphasise the importance of adapted conservative treatment which, in our experience, provides the better clinical outcomes.

Purpose of the study: Transfer of a vascularised fibular is an option after tumour resection to save the limb.

Material and methods: Thirty-eight consecutive cases of malignant bone tumours located in the shaft of long bones of the lower limb were treated with a free transfer of a vascularised fibula. There were 30 femoral localisations and 8 tibial localisations, 32 first-intention transfers and six transfers after failure of an allograft. Mean age at transfer was 11.8 years (range 4.33–22.57). Adapted chemotherapy was associated. The Musculo-skeletal Tumour Society score was noted for the functional assessment. Healing was considered achieved when there was a bone bridge between the transplant and the recipient bone associated with disappearance of the osteotomy line. Outcome was expressed as mean or percentage with the 95% confidence interval. P< 0.05 was considered significant.

Results: Mean follow-up for the 38 patients was 7.56 years (range 0.37–18.4). The mean MSTS was 27.2 (range 20–30).. This mean score was significantly higher (S t = 2.11> 2.04) for vascularised fibular transfer surgery immediately after tumour resection (27.4) than after revision surgery (25.4). The healing rate was 89%. The rate of healing failure of the vascularised free transfer was significantly greater (p=0.005< 0.05) after revision (33%) than after immediate transfer (6%). The rate of good results in the Boer classification was significantly higher for tibial than femoral reconstructions (p=0.006< 0.05), for immediate surgery than revision surgery (p=0.005< 0.05), and for Ewing tumours than for osteosarcoma (p=0.0019< 0.05).

Discussion: Free transfer of a vascularised fibula is a reliable reconstruction technique for bone shaft loss of the lower limb after resection of a malignant bone tumour in children. This is a mutilating surgery with frequent complications but which can save the limb. This reconstruction surgery should be done at the same time as the resection. Healing of the vascularised fibular transplant is more difficult to achieve for femoral reconstructions than tibial reconstruction and there are more complications in the femoral localisation. Femoral reconstructions using a vascularised fibular transplant should be associated with an allograft.

Thanks to neonatal screening, idiopathic congenital dislocation of the hip (CDH) is generally diagnosed and treated at an early age. Despite this measure, late diagnosis of CDH still occurs. The goal of this article is to analyse the results of Petit-Morel’s closed reduction (CR) technique in the treatment of CDH diagnosed between 1 and 5 years old. We reviewed 72 hips in 60 patients. The treatment method was the same for all patients, beginning by bilateral longitudinal traction to achieve ‘presentation’ of the hip. It was followed by ‘penetration’ in a hip spica cast made under general anesthesia. The third step was an almost systematic surgical treatment of the remaining acetabular dysplasia. Results were evaluated using the radiological Severin score. Average follow-up was 11.9 years. The failure of CR occurs only twice. In this two cases, open reduction showed intraarticular obstacles to reduction. The only case of avascular necrosis (AVN) occured in one of this two failures of CR. At last follow-up, 95.8% of hips were rated as normal, or midly deformed. Young age at treatment significantly influenced the prognosis in our series. Neither the gender nor the height of the dislocation did appear to have any influence on the result. The patients which did not undergo a periacetabular osteotomy were significantly younger than the other one in the series. Pelvic osteotomy is an integral part of the method, as after 18 months many hips have lost their capacity to correct the remaining dysplasia. However, we only perform this osteotomy if the hip shows no sufficient correction during the semesters following the reduction od the dislocation. Considering Severin score, it is impossible to privilege closed or open reduction, as the results of both methods are close. However, in case of failure of reduction, which occurs in both methods, a second open reduction is much more difficult to achieve than and open reduction in a hip first treated by closed reduction. The results of this second surgery on the hip are poorer, with higher rates of AVN. Moreover, long-term functional and radiological deterioration of the hip is higher after open reduction than closed reduction. Lowest rates of AVN are reported after traction followed by closed reduction compared with exteporaneous reduction or open reduction, thanks to progressive reduction of the hip. Finally, mention should be made of the cost of the treatment. Petit-Morel’s protocole is expensive, both because of the duration of stay in the hospital, and by indirect costs as parent adaptation of its work during the treatment. The cost of open reduction is lower. However, considering the prooved better results of the closed method, requiring lower rates of further surgical procedure, we think that this method is the one to be promoted for treatment of CDH in children between 1 and 5 years old.

Purpose of the study: The aim of this study was to evaluate the results of the repeated soft tissue release for recurrent postoperative idiopathic congenital talipes equinovarus. There is no real consensus on the appropriate therapeutic option.

Materials and Methods: Fifty two patients (74 feet) underwent revision surgery performed by our senior surgeon between 1974 and 2001. One, two or three soft tissue release procedures were performed on 59, 12 and 3 feet respectively. Mean age at the time of the revision surgery was 5.7 years (range 15m-14y). Triple deformity (varus, equinus, adductus) was found in 46 feet, while 28 feet had one dominant deformity. The operation consisted of complete release of the soft tissues in 26 feet and partial release in 48. Subtalar release was indicated in 21 feet. Lichtblau osteotomy was performed in 48 feet. The clinical and radiological outcome was assessed using the Ghanem and Seringe scores recorded before surgery and at last follow-up.

Results: Mean follow-up was 11 years (range 4–30). Complications included overcorrection in valgus (n=6) and recurrence (n=8). The anatomic correction was highly significant. Dorsoplantar X-rays show the improvements in the mean talocalcaneal divergence (18–21°), the mean talus-first metatarsal angle (reduced from 28° to 4°), and the calcaneus-fifth metatarsal angle (reduced from 20° to 2°). The average of tibiocalcaneal angle in lateral view increased from 1° to 10° and the average of calcaneal incidence from 6° to 9°. At last follow-up, outcome was considered as ‘excellent’ in 29% and ‘good’ in 42% of the cases. We had ‘fair’ results in 14 feet (19%) because of poor functional results in one third and anatomical defects in two-thirds of them. The outcome was considered ‘poor’ in seven feet (10%), which was due to significant anatomical defects. Triple arthrodesis was needed in seven feet after skeletal maturity.

Discussion and Conclusion. Repeated soft tissue release provides an effective means for correcting anatomical anomalies caused by recurrent postoperative talipes equinovarus. The mid-term results are however affected by functional limitations characterised by decreased range of motion and joint pain, particularly in ankle joint. Excessive subtalar release raises the risk of valgus overcorrection. A splint worn at night may be helpful for preventing the recurrence.

Purpose of the study: The posterior paraspinal approach to the lumbar spine was initially described and promoted by Wiltse for posterolateral arthrodesis of the lumbosacral junction in patients with spondylolisthesis. Despite technical improvements proposed by Wiltse, the muscular cleavage is still poorly localized in the sacrospinalis muscle. The purpose of this work was to provide a more accurate anatomic description of this spinal approach and to describe anatomic landmarks to facilitate execution of the procedure.

Material and methods: Fifty anatomic specimens were dissected (27 male and 23 female cadavers); 33 had been embalmed. The anatomy study used a bilateral approach to the spine. The exact anatomic localization of the muscle cleavage was noted. Measures were taken in relation to the mid line of the L4 spinatus process.

Results: In all specimens, the muscle cleavage lay between the multifidus and longissimus heads of the sacrospinalis muscle. A fibrous partition was noted in 88 of the 100 specimens. The mean distance from the mid line to the cleavage line was 4.04 cm (range 2.4–7.0 cm). The surface of the sacrospinalis muscle presented fine perforating arteries and veins in all specimens, directly in line with the cleavage plane. In 12 cases, a major posterior sensorial branch of the L3 nerve running to the skin was identified in the cranial portion of the approach.

Discussion: The muscle cleavage plane appears to be easy to localize for the paraspinal approach to the lumbosacral junction. Opening the aponeurosis of the latissimus dorsi near the mid line enables visualization of the perforating vessels in line with the anatomic cleavage plane of the sacrospinalis muscle. In our experience, this plane is situated on average 4 cm from the mid line. Hemostasis of these vessels is acceptable since the sacrospinalis muscle has a rich supply of anastomosed vessels. Care must be taken to avoid injury to the posterior sensorial branch of the L3 nerve which runs along the plane of the muscle cleavage.

Conclusion: In our opinion, this minimally hemorrhagic approach is perfectly adapted to non-instrumented fusion of the lumbosacral junction, particularly for spondylolisthesis in children and adults. Precise knowledge of the anatomy of this approach is a necessary prerequisite for successful execution.

Purpose of the study: We wanted to assess long-term outcome after treatment for Ewing tumor of the pelvis.

Material and method: We reviewed 62 patients aged 5 to 28 years treated from 1983 through 1993. There were 35 males and 27 males. Sixteen patients had pulmonary metastases at diagnosis. Patients were given chemotherapy using three protocols (Ew 84, Ew 88, Ew 93) proposed by the French Society of Pediatric Oncology. Fourteen patients were give high-dose chemotherapy with a bone marrow graft. The local treatment was not randomized. Radiotherapy was used alone in 25 patients and 15 underwent surgery and radiotherapy. Eighteen underwent surgery without complementary radiotherapy. For patients were not given local treatment. Outcome at last follow-up was assessed retrospectively.

Results: Mean follow-up was 6.6 years (3 months to 18 years); 29 patients were in remission, 6 had progressive disease, and 27 had died. Two patients who had bone marrow grafts developed a second tumor in the radiated territory. The overall chances of survival were 55±6% at five years and 53±7% at ten years. There was no significant difference by type of chemotherapy. In the group of operated patients, the five year survival was 68% versus 43% in the group of non-operated patients (p=0.007). In patients with initial metastases, chances of survival at ten years were 19.7±10% versus 65.9±7% in patients without metastasis. Only two patients who presented metastases initially were in remission at last follow-up. Five patients developed local recurrence after surgery and none had been radiated despite incomplete response to chemotherapy or presence of contaminated resections.

Discussion: Rigorous comparison between operated and non-operated patients is hindered due to the different indications. Results of treatment of Ewing tumors of the pelvis without metastasis are comparable to those obtained for tumors in other localizations. The fact that a second tumor can develop in the radiated territory is a particularly important factor in patients given high-dose chemotherapy with a bone marrow graft.

Conclusion: Surgical treatment appears to improve local control of Ewing tumors of the pelvis. If initial metastasis is not present, the prognosis appears to be similar to other localizations. Radiotherapy remains and indispensable adjuvant in the event of surgical resection or incomplete response to chemotherapy.

Purpose: Amputation is often proposed for malignant tumours of the distal tibia. The purpose of our study was to report outcome and complications after conservative treatment of osteosarcoma of the distal tibia.

Material and methods: Eight patients, four boys and four girls aged 8 – 16 years (mean 12 years) were managed conservatively with high-dose methotrexate chemotherapy for osteosarcoma of the distal tibia between 1983 and 1998. Wide resection was performed in all cases and one patient had a lung metastasis. Mean length of resection was 13 cm (9–19). Tibiotalar reconstruction arthrodesis was performed in seven patients. Tibial grafts and a centromedullar nail associated with fibulotalar arthrodesis with screw fixation were used in four patients. Plate fixation was used in two, and one patient had a cement spacer while waiting for biological reconstruction. After surgery, the patients were immobilised in a plaster cast for three to six months. Weight bearing began two to four months after surgery.

Results: Resection was wide in four cases, marginal in three , and contaminated in one. Four patients responded well to chemotherapy and four responded poorly. Outcome was assessed at a mean follow-up of 5.5 years (2–17 years). At last follow-up, six patients were in remission, and two had died, including one after local recurrence despite amputation. Three patients had a deep infection which cured in all three without surgery. Two revisions were required in one patient with nonunion before achieving a solid union. All the patients who had a tibiotalar arthrodesis progressively developed nearly normal “ankle” function subsequent to progressive sub-talar hypermobility. The mean MSTS score was 27.7/30 (range 22 – 30).

Discussion: Conservative management of osteosarcoma of the distal tibia appears to be feasible and provides excellent functional results despite an important risk of infection. Wide surgical margins requires a good response to chemotherapy. In case of doubt, reconstruction must avoid contaminating the rest of the tibia in order to allow secondary amputation if needed.

Purpose: Infection after resection and total knee arthoplasty for malignant bone tumours in children is a serious complication which may compromise limb salvage. The purpose of this work was to study the aetiology, treatment and prognosis of this event.

Material and methods: Among the 169 total knee arthroplasties performed for malignant bone tumours between 1981 and 1999, we selected 17 patients meeting the following criteria: proven infection with identified germ on deep samples or presence of a fistula more than two years after surgery. All of the patients had osteogenic sarcomas (excluding Ewing sarcomas which account for 30% of the tumours in this localisation). The bone tumour involved the femur (n=11) or the tibia (n=6) and required extraarticular (n=14) or transarticular (n=2) resection. Infections were primary (n=9) developing after the first operation, or secondary (n=8) to surgical revision in six, joint wound in one, or haematogeneous dissemination in one patient. The causal germ was identified in thirteen patients (76%) and was a staphylococcus in all cases. Treatment included systemic antibiotics and lavage (n=10), one-procedure change in prosthesis (n=3), removal of the implant with replacement by a spacer (n=2), surgical abstention (n=2), or amputation (n=1).

Results: Mean follow-up was eight years (2 – 16 years). On the average, treatment of infection lasted 51 months and required a 3.9 surgical interventions. At last follow-up, infection was considered cured in 70% of the patients who were free of clinical or laboratory signs of infection without antibiotics for at least one year. The arthroplasty could be preserved in one-third of the cases (22% of the primary infections and 50% of the secondary infections). Another treatment, arthrodesis (n=6), Borggreve procedure (n=1), or amputation (n=4), was given in the other two-thirds.

Discussion: The 10% complication rate observed here is in agreement with data in the literature. Development of primary infection is influenced more by the histology of the tumour and the presence of skin wounds (methotrexate) than by tumour site or type of resection. The diagnosis of primary infection is made late, often at the end of the postoperative chemotherapy protocol. Changing the implant is the ideal treatment. Secondary infection is characteristically less difficult to diagnose; infection is recognised earlier and the chances of preserving the implant are better.

Purpose: Therapeutic options for shaft reconstruction are allografts, shaft prosthesis, and autografts, which may be vascularised or not. The purpose of this work was to assess mid-term results and complications after upper limb reconstructions using a vascularised fibula in children and adolescents undergoing surgery for tumour resection.

Material and methods: A vascularised fibular graft was used for reconstruction in ten patients who underwent surgery for resection of upper limb tumours between 1994 and 2000. The patients were seven boys and three girls, aged seven to seventeen years. the vascularised fibula was used for reconstruction after tumour resection in the same operation for eight patients and to salvage a proximal humeral prosthesis in two patients. The eight single-procedure reconstructions concerned four resections of the humeral shaft and four resections of the radius. Tumour histology was: classical osteosarcoma (n=7), low-grade osteosarcoma (n=1), Ewing tumour (n= 1) and aggressive enchondroma (n=1). Six patients were on chemotherapy at the time of the fibular transfer.

Graft lengths varied from nine to 21 cm (mean 14 cm). Plate fixation was used in most cases. All patients wore a cast for six to twelve weeks after surgery.

Results: Results were analysed retrospectively after 3.9 years follow-up (range 1 – 7 years). Mean time to bone healing was three months (range 1.5 – 5 months). Five of the six humeral shaft reconstructions fractured due to trauma, requiring revision surgery in four cases. All patients who were reoperated achieved bone healing rapidly. One radius had to be revised to add supplementary bone. The mean functional score (MSTS) was 25.5/30 (range 21 – 30). One patient died from lung metastasis and the others exhibited complete tumour remission.

Discussion: Vascularised fibula reconstruction of the upper limb provides good radiological results, particularly for the radius. For the humerus, the results are better for younger children because the bone can grow in thickness. Certain mechanical complications may occur if normal sports activities are resumed too early. Functional outcome after these shaft reconstructions is nearly normal.

Purpose: Use of massive knee prostheses in the treatment of malignant tumours allows excellent short-term oncological and functional results. The purpose of our work was to demonstrate that these good early results later require several revisions.

Material and methods: From 1981 to 1986, 48 patients, mean age 13.8 years (9–19) were treated for osteosar-coma of the knee by chemotherapy and resection. Six patients had metastases at the time of diagnosis. Resection involved the distal femur in 34 cases, the proximal tibia in 13 and both extremities in one case. Mean resection was 20 cm (12–29). Reconstruction was achieved with a cemented GUEPAR. Twenty of the initially implanted prostheses had a rotatory mechanism. Reconstruction of the diaphyseal segment was generally achieved with massive metal or polyethylene prostheses and in three cases with a prostheses sleeved on an allograft. After resection of the proximal tibia, reconstruction of the extensor system was achieved with the vastus medialus.

Results: Results were assessed retrospectively at a mean follow-up of eleven years (4 months – 20 years). Seven patients were lost to follow-up. At last follow-up of available patients, 34 were in remission, 14 had died, giving an actuarial survival rate at 15 years of 72%. For the 48 prostheses initially implanted, seven were revised for loosening, four became infected (two secondarily), four femoral stems fractured and two rotatory mechanisms fractured. All the prostheses followed more than three years required at least one surgical revision. Only eight of the initially implanted prostheses are still in situ after 15 years, giving an actuarial survival probability of 39±17%. Certain prostheses were changed four times. If all revisions are included, the 32 surviving patients have had 84 prostheses. Most of the recent revisions were indicated for hinge wear and to avoid changing the inserts within too short an interval. At last follow-up, one patient has undergone amputation, one has a rota-tionplasty, and one has an arthrodesis, all for infection. The functional results at last follow-up are good or excellent in 19 cases, fair in five, poor in three and could not be evaluated in 21 (14 deaths and seven lost to follow-up).

Discussion: Reconstructions using massive prostheses are associated with a high rate of mechanical complications making surgical revision inevitable. These complications are mainly due to wear of the hinge itself. The use of better designed prostheses in terms of mechanical properties should reduce the rate of mechanical complications. When the tumour extension spares the epiphysis, use of biological, non-prosthetic reconstruction methods should be preferred.

Methods and results: From the last 15 years, we have observed 18 cases from various aetiologies of compression of the airway by the “billot” created by the protrusion of the vertebral bodies inside the thoracic cage. This status lead to atelectasia intermittent or permanent with subsequent recurrent lung infection and sometimes abscesses with impairment of the respiratory function perfectly demonstrated by CT scan as well as with bronchoscopy showing extrinsic bronchi stenosis. Such pathology necessitates an anterior vertebral body resection for decompression of the airway done in 15 patients and sometimes partial lung removal lobectomy done in 4 cases. Subsequently repeated lung infection disappeared in all cases but vital capacity only improved by 2%.

Discussion: This pushed us to study this point and to propose a new 3D entity called spinal penetration index seen as well on regular CT scan cut of the chest as on 3D volumetric reconstruction representing the amount of vertebral, rib, soft tissues and sometimes empty space protruding inside the thoracic cage. This presented as an endothoracic vertebral hump compared to the exothoracic classical rib hump. Compared to normal subject where the amount is less than 10%, it can reach 50% in some severe scoliotic cases. The deformity is evident and can be quantified easily with a computer programme. Done today with regular CT scan cuts at rest, in the near future this will be obtained with regular stereographic X-rays in a much less invasive manner with low dose radiation.

Conclusion: The spinal penetration index measure in 3D is the amount of protrusion of the spine and surrounding tissues inside the thoracic cage. It is an anatomical parameter entering into the measurement on the useful thoracic volume for breathing given by the thoracic skeleton. It is very different from vital capacity where diaphragm, joints, muscle function play an important role. This concept allows to quantify in 3D the results of surgery of the spine in a much better way for 3D consideration than the classical Cobb angle. It helps also for analysis of the chest for example before and after thoracoplasty and allows to classify the rib hump and the vertebral hump in a logical way with their therapeutic consequences.