Purpose of the study: Nonunion, which is a biological failure, requires revision, usually an aggressive operation. Haematopoietic bone marrow contains colony forming unit fibroblasts (CFU-F) which could favour bone healing. The purpose of this work was to determine whether a minimally invasive procedure, injection of CFU-F into the nonunion space, could favour bone healing without further procedure.

Material and methods: Our series included 43 patients: 36 male and 7 female, mean age 39.9 years. Forty-seven atrophic and aseptic nonunions of long bones were treated with percutaneous injection of concentrated autologous bone marrow: 27 tibias, 17 femurs, 3 humeri. Bone marrow was harvested from the posterior iliac crests (346 ml) then centrifuged to keep the leuko-platelet fraction (78 ml). This concentrate was injection into the nonunion space under radioscopic guidance. Efficacy was assessed on the basis of clinical criteria (complete pain-free weight-bearing, absence of contention, absence of mobility) and on radiographic criteria (healing of 3/4 corticals).

Results: Thirty nonunions healed: 19 tibias (70%, 11 femurs (65%) and 0 humerus. Mean time to healing was 5.9 months (2.4–15.6). Factors of poor prognosis were: smoking, alcohol, diabetes, corticosteroids, radiotherapy, history of sepsis (p=0.01). Early grafting increased the chances of success (p=0.04). Age, initial skin opening, type of fixation did not have a significant impact on healing. The number of CFU-F had an effect on the rate of healing.

Discussion: This technique is effective for the treatment of nonunion of the lower limb, allowing bone healing in two thirds of the cases with a minimally aggressive procedure. The method is easy to perform but requires a rigorous technique for the different phases of puncture, concentration and reinjection. Nonunions unresponsive to conventional methods, and thus corresponding to multifactorial problems, probably constitute the limitation of this method. Cell expansion or differentiation techniques could be helpful in improving the success rate but at the present time the osteogenic potential of these cells remains to be elucidated as a function of their stage of maturation.

Conclusion: Percutaneous grafts of concentrated autologous bone marrow can be a useful contribution to the therapeutic armamentarium for nonunion. Morbidity is low and the method does not compromise future options. It can be proposed as a first-intention solution for the treatment of long bone nonunion.

Purpose of the study: The right position of total hip arthroplasty (THA) implants affects short-, mid- and long-term outcome and complications. Navigation can improve implant position relative to a reference plane, in particular during mini-invasive implantation. The purpose of this work was to compare the position of the prosthetic cup in two series, one implanted with a navigation system and one with the conventional technique.

Material and method: The same surgeon performed the operations in each group of 42 patients (matched for age, gender, BMI, side). In the historic non-navigated series, a press fit femoral implant was used (Excia). The cups were either press fit (Ovalock or Plasmacup), or cemented with polyethylene inserts. The Hardigne incision (15 cm) was used for the conventional implantations. In the prospective navigated series, a press fit femoral element (Excia) and a press fit cup (Plasmacup) were implanted. The Orhtopilot navigation system was used (reference plane: Lewinnek anterior pelvic plane). The adapted Hardinge incision (5 cm) was used for the mini-invasive implantations. Inclination was measured on the weight-bearing pelvis relative to the radiological U line; the Pradhan method was used for anteversion. The objective was to achieve 45° horizontal inclination and 15° anteversion.

Results: In the non-navigated series, the inclination was 53±8 and in the navigated series 44±5.6. On average, inclination decreased significantly (8). Anteversion in the non-navigated series was 7±4, and 12±5.3 in the navigated series. On average, anteversion increased by 6 (statistically significant). The number of cups in the Lewinnek safety zone was 21 of 42 (50%) in the non-navigated series and 38 of 42 (90%) in the navigated series (statistically significant). The increase in leg length was 6.2 mm in the non-navigated group and 4.4 in the navigated group.

Discussion: Positioning did not take into account the preoperative analysis of the hip, but could adapt to scanner or EOS data. Navigation should also integrate offset, femoral position, and leg length.

Conclusion: Navigation of the prosthetic cup improves precision positioning in relation to the reference objectives, in particular, for mini-invasive surgery.

Purpose of the study: Basimetatarsal osteotomy to correct hallux valgus deformity by subtraction of a lateral wedge does not take into account the distal angle of the first metatarsal (DMMA). The purpose of this study was to demonstrate that the preoperative DMMA has an effect on the correction of the metatarsophalangeal angle and the duration of the result.

Material and methods: This retrospective study included 76 patients, mean age 58 years (84 feet). The M1P1 angle of the first ray was 34 on average, the DMMA 10 (two-thirds of the patients had a DMAA > 10. The same operator used the same technique for all procedures: lateral wedge osteotomy of the base of the first metatarsal with metatarsophalangeal release. Basal osteotomy of the first phalanx was performed for severe deformity. Radiographic measures were made on the dorsoplantar anteroposterior images in the weight-bearing condition preoperatively, at four weeks and at last follow-up. All images were read by an independent observer. Mean follow-up was 11 months. The DMMA measurement was the angle between the distal joint surface of the first metatarsal and the alignment of its diaphysis.

Results: Mean postoperative correction of the hallux valgus was 25 with a mean M1P1 of 9. This result remained stable without loss of correction at last follow-up. The mean postoperative DMAA was 10 and remained unchanged.

Discussion: Determination of the DMAA can be difficult because of preoperative pronation of the forefoot, compromising the reliability of the measurement. The literature also reports intraobserver and interobserver variability of this angle. Mean follow-up was not greater than one year, but the loss of correction generally occurred during the first six postoperative months. The operative technique enabled sufficient and stable correction over time. A pathological value for DMAA, even if large and uncorrected, does not prevent a good correction of the M1P1 angle and to maintain that correction. The clinical result is also the same irrespective of the preoperative DMMA.

Conclusion: Wedge osteotomy of the base of the first metatarsal is a reliable procedure for the treatment of hallux valgus. The value of the DMAA has no effect, in our experience, on the quality of the correction, or on the duration of the result.

Navigation technology is a new tool which can help surgeons to a more accurate hip component implantation and a better reproducibility of the procedure.

The purpose of this study was to compare conventional and navigated technique and a new developed straight hip stem for uncemented primary total hip replacement.

The results of two consecutive implantation series of 42 patients (non navigated) and 42 patients (navigated) were analysed for implant positioning and short term complications. Non navigated components were implanted through conventional incision (15 cm), navigated component by minimal invasive surgery (5 cm). All surgeries were performed through Hardinge approach and by a single senior surgeon.

Radiographic analysis of cup position showed a significant improvement with reduced radiological inclination (53° non navigated/44° navigated, p< 0.001) and higher anteversion (7° non navigated/12° navigated, p< 0.001). The mean postoperative limb length difference was 6.2 mm (SD 9.0, non navigated) and 4.4 mm (SD 6.4, navigated). Intraoperative and early postoperative complications were not different. No dislocation occurred in both groups. There was one intraoperative trochanter fracture which was not revised (non navigated) and one revision because of a periprosthetic fracture caused by fall down during rehabilitation (navigated).

We conclude that acetabular implant positioning can be significantly improved by the use of navigated surgery technique even in minimal invasive surgery condition. The data for postoperative limb length difference was still similar but within the expected range in both groups. Navigation technology seems essential for minimal invasive surgical procedure yielding help and security to the surgeon. The effect of improved cup positioning on mid and long term results for both groups have to be further investigated.

Introduction: A good cup positioning requires reliable anatomical landmarks expecially for navigation. The anterior pelvic plane (APP) seems to be a good reference for navigation because it is in relation with pelvic tilt which do affect the position of the cotyle and consequently the position of the cup. The value of this plane is not well known according to gender, age, weight… The aim of the study is to assess radiologically the APP in standing and supine position before and after total hip arthroplasty.

MATERIALS AND Methods: 92 Patients (32 males, 60 females, mean age 65 years) underwent strict lateral X-rays in standing and supine standardized position. Uninterpretable or unsatisfying X rays were withdrawn. 45 patients underwent a standing X-ray, 24 a supine X-ray, 21 a supine and standing X ray. Statistical analysis used a Student t-test.

Results: Non matched values showed a retroversion of the pelvis of 6.4° (+/− 6.9) in supine position, 0.3° (+/− 7.4) in standing position. Matches values showed an retroversion of the pelvic of 6.9° (+/− 5.3) in supine position, 0.3° (+/− 5.03) in standing position (significant difference). Extreme values varied from −15° to + 18° (3 patients showed no variation, 2 patients a retroversion from supine to standing position). There was no statistical difference between male and female but a statistical differences in females.

Discussion: The APP is easily assessable by X rays in standing as in supine position. Bony landmarks of the plane are also assessable by navigation tools and to can be a good plane as reference. Several authors showed the repercussion of the pelvic tilt on the cotyle position. The difference between standing and supine position is about 6°. But for some patients the difference is may be of 20°and that could explain some impigment and instability. A cup well positioned in supine position may be not so good in standing position because of the pelvic tilt.

Conclusion: The value of the APP is important to know before THA and seems to be a good plane as reference for navigation.