Despite advances in total hip arthroplasty, failure of acetabular cup remains a concern. The role of bone marrow stromal cells (BMSCs) to aid osseointegration of orthopaedic implants have been recently studied. We investigated the hypothesis that autologous BMSCs sprayed on the surface of acetabular cups would improve bone formation and bone implant contact.

Total hip replacements were implanted in 11 sheep, randomly assigned to receive either acetabular implants sprayed with autologous BMSCs suspended in fibrin (study group) or fibrin only (control group). Sheep were sacrificed after six months and the acetabulum with the implant was retrieved and prepared for undecalcified histology. Implant bone contact in both groups was compared microscopically, by noting the presence or absence of new bone or fibrous tissue along the implant at 35 consecutive points (every 1000 μm). The observers undertaking the histological analysis were blinded.

Significantly increased bone implant contact was noted in the BMSC treated group 30.71% ± 2.95 compared to the control group 5.14% ± 1.67 (p = 0.014). The mean thickness of fibrous tissue in contact with the implant was greater at the periphery 887.21mm ± 158.89 and the dome 902.45mm ± 80.67 of the implant in the control group compared to the BMSC treated group (327.49mm ± 20.38 at the periphery and 739.1 mm ± 173.72 at the centre). Conversely, direct bone contact with the implant surface was significantly greater around the cups with BMSCs.

Our data demonstrate that BMSC sprayed on surface of acetabular implants improves bone implant contact. Spraying acetabular cups using stem cells could be used in humans where acetabular bone contact is compromised such as in revision procedures.

The radiological evaluation of the anterolateral femoral head is an essential tool for the assessment of the cam type of femoroacetabular impingement. CT, MRI and frog lateral plain radiographs have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of the cam type of impingement and may also be used as an assessment for the successful operative correction of the cam lesion.

We studied the alpha angles of 32 consecutive patients with femoroacetabular impingement. The angle measured on frog lateral radiographs using templating tools was compared with that measured on CT scans in order to assess the reliability of the frog lateral view in analysing the alpha angle in cam impingement.

A high interobserver reliability was noted for the assessment of the alpha angle on the frog lateral view with an intraclass correlation coefficient of 0.83. The mean alpha angle measured on the frog lateral view was 58.71° (32° to 83.3°) and that by CT was 65.11° (30° to 102°). A poor intraclass correlation coefficient (0.08) was noted between the measurements using the two systems.

The frog lateral plain radiograph is not reliable for measuring the alpha angle. Various factors may be responsible for this such as the projection of the radiograph, the positioning of the patient and the quality of the image. CT may be necessary for accurate measurement of the alpha angle.

Purpose of study: The aim of this study was to look at the clinical outcome of PLC interference screws in knee ligament reconstruction surgery.

Materials & Results: We prospectively followed up 60 patients who underwent primary anterior cruciate ligament (ACL) reconstructions using PLC (Calaxo; Smith & Nephew) screws to secure the graft in the tibial tunnel. [(35 male patients & 25 female). Average age 33.72 years]. In addition to the ACL, PLC screws were used to reconstruct the posterior cruciate ligament in one case and posterior cruciate ligament with the posterolateral corner in another three patients. Hamstring autografts were routinely preferred except in multiple ligament reconstructions, when allografts were also used.

25 (41.67%) patients presented with complications (synovitis in 10 patients, prominent tibial swelling in 21 patients and both in 7 patients). In comparison, no complications were noted in 60 other age and sex matched patients in whom PLLA (Bio RCI; Smith & Nephew) screws were used by the same surgeon.

The symptoms in the PLC screw group often settled conservatively and did not affect knee stability. 6 patients underwent exploration of the tibial tunnel site. A sterile white cheesy substance was noted which was removed, leaving an empty tibial tunnel. The ACL graft was found to be well attached to tibial tunnel in all cases. The PLC screw size did not have any correlation to the occurrence of complications. 2 patients required multiple washouts, one of whom developed a deep infection.

Conclusion: The degradation of PLC screws does not follow the gradual and controlled pattern demonstrated in the ovine model [Walsh WR et all, Arthroscopy. 2007 Jul;23(7):757–65. Comparison of PLLA and PLC interference screws in an ovine ACL reconstruction model.]. The unpredictable screw resorption, and the reaction to it can lead to serious clinical consequences.

Purpose of study: The all inside fixation of meniscal tears with bio-degradable products is popular because of its fast application and reduction in risks of serious neurovascular complications. We reviewed the results of a consecutive series of all inside meniscal repairs performed by the senior author in a carefully selected patient population.

Materials & Results: The senior author performed 104 consecutive meniscal repairs (54 lateral & 50 medial meniscus) in 96 patients (66 male, 30 female), using all inside meniscal repair systems (18 Bionxx, 86 FasT Fix; Smith & Nephew). The average patient age at the time of repair was 31.6 years (range 17 – 46 years). On an average 2 arrows (range 1–4) were used in the Bionnx system and 2.5 sutures (range 1–7) for the Fas T fix system. The predominant tear pattern was a peripheral red on white type tear involving the body and posterior horn. Concomitant ACL reconstruction was undertaken in 50% cases. In 26.9 % cases the repaired meniscus was partially trimmed prior to repair and in 25 % cases a tear of the non repaired meniscus was stabilised by trimming alone. A further arthroscopic partial menisectomy was performed in 12 cases of failed repair (4 Bionxx, 8 Fas T fix) at an average of 16.16 months (range 1 month – 44 months). None of the other patients had symptoms or signs suggestive of meniscal pathology on follow up (minimum 12 months). The repair was successful in 90.69 % of Fas T fix repairs and 77.78 % of Bionxx repairs. The meniscal repair failure rate in the group which had an ACL reconstruction was 5.77 %. No major intra or post operative complications were noted.

Conclusion: Successful meniscal preservation is feasible by using an all-inside meniscal repair device. Patient selection and due consideration to the site and geometry of the meniscal tear is crucial.

Purpose of study: The diagnosis of meniscal tears is usually based on the patient’s history and on specific physical tests. Magnetic resonance imaging (MRI) and arthroscopy is often necessary for diagnosis.

Theofilos Karachalios et al. described the new ‘Thessaly test’ and concluded that it could be safely used as a first line screening test for the selection of patients who need arthroscopic meniscal surgery (Ref: J Bone Joint Surg Am. 2005 May; 87(5):955–62). Our objective was to study the role of physical diagnostic tests in screening for meniscal tears and to validate the diagnostic accuracy of the Thessaly test.

Methods & Results: We examined 109 patients [(80 male, 29 female), average age 39.11 years, range (16–66)] who presented with a history suggestive of a meniscal tear. Joint line tenderness,

McMurray’s test and the Thessaly test were assessed by an independent investigator blinded to any imaging data in all patients. MRI and subsequent arthroscopy results were then collated.

Our study showed a much lower diagnostic accuracy for the Thessaly test (61.25 % for medial meniscus and 80 % for lateral meniscus) It is comparable to McMurray’s test (57.14 % for medial meniscus and 77.38 % for lateral meniscus). The Joint line tenderness test has a far superior diagnostic accuracy (80.95 %for medial meniscus and 90.48 % for lateral meniscus). Combining the joint line tenderness test with McMurrays test or the Thessaly test further increased the diagnostic accuracy. Magnetic resonance imaging (MRI) detected 96% of meniscal tears. Arthroscopy was diagnostic and therapeutic in all cases.

Conclusion: Physical tests may not always be diagnostic of meniscal tears. MRI and arthroscopy may be essential in dubious clinical presentations. In our study the Thessaly test in isolation did not have the highest diagnostic accuracy for the detection of meniscal tears but helps increase diagnostic certainty when combined with standard tests.

Introduction: Aseptic loosening at the bone-implant interface of THA acetabular components is a significant cause of implant failure. This loosening has been attributed either to wear particle-induced osteolysis or to the effects of joint fluid-pressure. It may be possible to prevent the loosening of implants by improving fixation between the bone and implant, or promoting the growth of a biological bony seal, in order to prevent the influx of wear particles or pressurized joint fluid. Additionally in revision implants it is important to promote osseointegration in situations where bone stock may be limited. The hypothesis of this study was spraying autologous BMSCs in fibrin glue onto the surface of HA-coated acetabular components would increase bone formation around the implant and improve bone-implant contact.

Materials and Methods: Bone marrow was aspirated from the iliac crest of six goats, and BMSCs isolated and expanded in vitro. 10 x 10e6 BMSCs were suspended in reconstituted thrombin pre-operatively. A standard posterior approach was used. The acetabular shell was then coated with 2 ml of fibrin glue, with (n=6) or without 10 x 10e6 autologous BMSCs (n=6), and the acetabular component impacted into position. Antibiotic and analgesic prophylaxes were carried out. All animals were weight bearing within 48 hours post-operatively. Walking and ground reaction forces were assessed pre-operatively, as well as 6 and 12 weeks post-operatively. Results were expressed as a percentage of force transmitted through the right leg versus the left leg. After 12 weeks, the acetabulae were retrieved, and processed for histology. The percentage of new bone around the cups was measured within 5 radial zones, using image analysis. Bone-implant contact was also analysed between the new bone and implant surface. Mann Whitney U test was used to show statistical significance.

Results: New bone formation in Zone 5 showed a significant increase in the BMSC group (71.97±10.91%), when compared to the controls (23.85±15.13%, p=0.028). The other zones did not show a significant difference. Overall new bone growth in the BMSC group was 30% greater than the control group (71.42±8.97% and 54.22±16.56%, respectively, p=0.58). Bone-implant contact was significantly improved in the BMSC group (20.03±4.64%), in contrast to the control group (13.71±8.32%, p=0.027). With regards to the force plate analysis, there was no significant difference in loading between groups at both 6 weeks (Controls-79.74±3.63%, BMSCs-59.39±9.33%, p=0.086) and 12 weeks (Controls-86.0%±2.85%, BMSCs-62.33±5.12%, p=0.055).

Discussion and Conclusions: In this study, overall bone growth was greater when cups were treated with BMSCs. Bone-implant contact was significantly improved as well. This study has clinical applications, as using MSCs in fibrin glue promotes a bony seal in contact with the implant which may prevent the migration of particles, or joint fluid, decreasing the likelihood of aseptic loosening of THAs, and improving their longevity. Also, this technique may improve fixation in situations where bone stock is reduced.