Purpose: Chondral injuries of the knee are commonly seen at arthroscopy, yet there is no consensus on the most appropriate treatment method. However, untreated cartilage injury predisposes to osteoarthritis contributing to pain and disability. For cell-based cartilage repair strategies, an ex-vivo expansion phase is required to obtain sufficient numbers of cells needed for therapy. Although recent reports demonstrated the central role of oxygen for the function and differentiation of chondrocytes, little is known of the effect of physiological low oxygen concentrations during the expansion of the cells and whether this alters their chondrogenic capacity.

Method: Initial studies of chondrocyte expansion were performed in mature mice, with cells expanded at either atmospheric oxygen tension (21%) or 5% 02 in monolayer cultures. Chondrogenic differentiation was subsequently assessed via micromass culture. Having determined that oxygen tension influences murine chondrocyte expansion and differentiation, similar studies were conducted using adult human chondrocytes taken from knee arthroplasty off-cuts, with mRNA expression of select genes involved in the chondrogenic program analyzed by q-PCR.

Results: Cellular morphology was improved in hypoxic culture, with a markedly more fibroblastic appearance seen after greater than 2 passages in 21% O2. Micromass cultures maintained in hypoxic conditions demonstrated stronger staining with Alcian blue, indicating stronger expression of cartilaginous glycosaminoglycans. Collagen type II mRNA expression was two-fold higher in cells expanded at 5% as compared to expansion at 21% O2. Micromass cultures grown at 21% O2 showed up to a twofold increase in the tissue content of glycosaminoglycans when formed with cells expanded at 5% instead of 21% O2. However, no differences in the mRNA expression or staining for collagen type II protein were observed in these micromass cultures. Hypoxia (5% O2) applied during micromass cultures gave rise to tissues with low contents of glycosaminoglycans.

Conclusion: In-vivo, chondrocytes are adapted to a hypoxic environment. Taking this into account, applying 5% O2 in the expansion phase in the course of cell-based cartilage repair strategies, may result in a repair tissue with higher quality by increasing the content of glycosaminoglycans.

Objectives: To compare the results of various surgical approaches to the knee in primary total knee arthroplasty (TKA) surgery.

Design: Systematic review with meta-analysis.

Data Sources: Cochrane Bone, Joint, and Muscle Trauma group trials register (2007), Cochrane central register of controlled trials (Cochrane Library issue 2, 2007), Medline (1950–2007), Embase (1974–2007), CINAHL (1982–2007), Pubmed, SCOPUS and ZETOC.

Review Methods: Randomised and quasi-randomised controlled trials comparing surgical approaches in patients undergoing primary TKA. Relative risks and 95% CIs were calculated for dichotomous outcomes, and weighted mean differences and 95% CIs calculated for continuous outcomes. Individually randomised trials were pooled whenever possible with the use of the fixed-effects model of Mantel-Haenszel.

Results: 53 articles were identified using our search strategy; of these, 32 were excluded from the systematic review. 21 trials involving 1082 patients (1170 TKAs) were included.

Midvastus (MV) vs Medial Parapatellar (MPP) approach:

Quadriceps function in the early post operative period was better preserved in the MV group. Post operative pain, blood loss and the need for LRR tended to be lower in the MV group.

Conclusions: Approaches preserving the quadriceps tendon improve the early extensor mechanism function and tend to decrease the need for LRR. Combined with a decrease in blood loss and postoperative pain, these approaches improve early rehabilitation and allow for a more rapid recovery of knee function. However, these early improvements fail to provide any long term benefit, do not improve knee scores, or decrease the length of hospital stay.

MIS tends to result in an improved early quadriceps function and decreased blood loss. However, these approaches are technically more demanding, result in longer operative times and provide no long-term benefit. There is concern that they result in a greater number of major complications and risk implant mal-alignment. Eversion of the patella seems to correlate with poor quadriceps function.

Aim: To assess the safety and clinical and radiological outcome of the TruFit CB porous, resorbable scaffold for symptomatic osteochondral and chondral articular defects in the knee.

Methods: 11 active sporting patients underwent cartilage repair using TruFit CB plugs (Smith & Nephew) for symptomatic defects on the medial or lateral femoral condyle. All had failed previous treatment (debridement/microfracture) and had persistent symptoms. Postoperatively patients were touch weight bearing for 2 weeks and partial until 4 weeks. Data was collected prospectively. The mean age was 34 (range 19 – 50) and 5 were male. Four lateral femoral condyle defects were treated, all associated with lateral meniscal tears. Four medial defects were associated with ACL injury (1), PCL injury (1) or isolated chondral injury (2). Single plugs were required in 5 (9mm in 3 and 7mm plugs in 2), 2 patients required 2 plugs (9mm and 7mm), and 2 required 3 (2×9mm + 1×7mm).

Results: All 11 patients were improved at a mean follow up of 14.5 months (3–21 months) with 4 currently back to full pre-injury level of sport. Subjective IKDC scores improved from 45 pre-op to 79 post-op (p< 0.05), Lysholm from 47 to 71 (p< 0.05), and latest Tegner activity score at 5. MRI evaluation including T2 mapping demonstrates reformation of the subchondral lamina and resorption of the graft. 2nd look arthroscopy was undertaken in 2 showing a well healed and well integrated surface.

Conclusion: These preliminary results indicate that TruFit CB plugs offer a potential solution for small focal chondral defects, offering an alternative to microfracture or osteochondral grafting with advantages of low morbidity and rapid recovery without the need for prolonged non-weight bearing.

The purpose of this study was to investigate the safety and outcome of bilateral simultaneous ACL reconstruction. In patients presenting with an ACL-deficient knee, 2 – 4% have bilateral ACL deficiency. A staged or simultaneous approach can be adopted when the patient requires reconstructive surgery for both knees. We report a case series of 8 patients (6 male, 2 female, average age 30.4 years) who underwent bilateral simultaneous ACL reconstruction.

Simultaneous or bilateral ACL reconstruction using ipsilateral patella tendon graft has been reported as a safe procedure with outcome and complication rate no different to unilateral procedures. Considerable cost savings of simultaneous over staged procedures have also been described. There are no case series in the published literature that describe the use of hamstring tendon autograft for bilateral simultaneous ACL reconstruction.

We used two camera stack systems and instrument sets to allow for simultaneous bilateral surgery by two surgical teams. Quadrupled hamstring tendon graft was used in 4 patients although in one patient patella tendon graft was used on the second side due to poor quality of hamstring tendons. Patella tendon graft was also used in a further 4 patients. At two weeks all patients were able to discard crutches and were independent in mobility. There was no difference in outcome at one year between those patients undergoing bilateral simultaneous ACL reconstruction in comparison to the outcomes of unilateral ACL reconstruction with respect to Lysholm, Tegner and IKDC scores. The mean follow up period was 2.3 years.

Our results demonstrate that bilateral simultaneous ACL reconstruction is safe and cost effective. A simultaneous approach also has the benefit of reducing the overall period of rehabilitation required by the patient. We report good short-term functional outcome but no long-term data is yet available.

Aim: To assess the results and complications of the opening wedge form of distal femoral varus osteotomy (DFVO) in treating valgus arthritis and ligament instability of the knee.

Methods: Patients undergoing DFVO were assessed prospectively using validated scoring systems and pre/post operative alignment radiographs. All had failed non operative and arthroscopic procedures and were keen to avoid arthroplasty. The lateral based opening wedge osteotomy aimed to correct the weight bearing line to position 50% medial to lateral and was held with either the Puddu femoral plate (Arthrex UK) or the Tomofix plate (Synthes UK).

Results: 26 distal femoral osteotomies were performed in 23 patients with a mean age of 34 (16 –58). The mean duration of follow up is 32.5 months (1–72). 8 were undertaken for primary valgus malalignment, and 15 for secondary valgus with OA due to previous lateral menisectomy. Simultaneous additional procedures included microfracture (3), MACI (1), meniscal transplantation (1), and MCL advancement (1). Mean hospital stay was 4 days (2–6). Post op alignment was out by greater than 10% of intended in 2/3. 3 early major complications required re-operation: 2 for plate and screw cut out and 1 for infection. 2 developed delayed union requiring bone grafting. Failure with conversion to arthroplasty has occurred in 2 (1 lateral UKA, 1 TKA), and 2 patients are awaiting either multi-ligament reconstruction or collagen meniscal implantation. The overall mean Tegner score is 4 (2–6), and 20 of the 23 patients feel satisfied with the outcome having avoided arthroplasty.

Conclusion: Opening wedge DFVO is a technically difficult procedure with significant complications, but in the right indication offers long lasting pain relief and joint preservation prior to arthroplasty. New techniques including accurate closing wedge fixation systems and computer guided operative planning and surgery may offer improvements to this vital surgical option.

Aim: To characterise the reasons for failure following primary surgical stabilisation, the indications and the results of surgery in a subgroup of patients undergoing revision arthroscopic shoulder stabilisation.

Methods: All patients who underwent revision shoulder stabilisation over a 3 year period were included in the study. Information about the index procedure, imaging and the findings at arthroscopy were used to characterise the mechanism of failure. Patients were assessed clinically and WOSI scored at 6 and 12 months and then annually.

Results: Thirty-six patients were reviewed. Twenty underwent an arthroscopic (AR) and 15 underwent an open (OR) revision procedure. The AR index procedures were 15 arthroscopic (4 suture-anchor, 10 thermal shrinkage, 1 unknown) and 5 open (3 Bankart, 2 Putti-Platt). The OR index procedures were arthroscopic 10 (4 suture-anchor, 3 transglenoid, 2 thermal shrinkage) and 6 open (4 Bankart, 2 Putti-Platt). Soft-tissue failure was the primary mechanism in all AR cases (4 further trauma, 7 inappropriate primary procedure, 3 missed pathology, 6 technical error). The OR primary mechanism of failure was bone loss 12 (4 epileptic) and soft-tissue failure 3. At AR follow-up of 25.8 months (10–45) there had been 1 re-dislocation and 1 subluxation, mean WOSI 298 (68–517). There had been no OR re-dislocations at 22.5 months (10–42) follow-up, mean WOSI 313 (76–621).

Conclusion: Recurrent instability following surgical stabilisation maybe due to bone loss or soft-tissue failure (further trauma, inappropriate primary procedure, missed pathology, technical error). Revision arthroscopic surgery maybe indicated in soft tissue failure cases and can produce acceptable medium term results.

Aim: To characterise the reasons for failure following primary surgical stabilisation in a group of patients considered suitable to undergo revision surgical stabilisation using arthroscopic techniques.

Methods: Patients presenting to our institution following failure of a primary shoulder stabilisation who underwent a revision arthroscopic stabilisation were reviewed. Information about the index procedure, imaging and the findings at arthroscopy were used to characterise the mechanism of failure. Shoulders were assessed pre-op by clinical examination and the WOSI score. At the time of arthroscopy patients proceeded to an appropriate stabilisation procedure using either a suture anchor or a modified transglenoid technique. Shoulders underwent a standard rehabilitation protocol and were reviewed at 6 weeks and then 6 monthly.

Results: Twenty patients underwent a revision arthroscopic stabilisation and were included in the study. Index procedures were arthroscopic stabilisation 4, thermal shrinkage 10 (un-repaired Bankart in 6), open Bankart 2, Putti-Platt 2, unknown procedure 2. Time from index procedure to re-dislocation ranged from 3 months to 7 years. The mechanism of failure was due to soft-tissue problems in all cases and could be grouped into four different categories. Further trauma 4 Inappropriate primary procedure 7 Missed pathology 3 Technical error 6 At early follow up of 6 – 42 months following revision arthroscopic stabilisation 1 patient re-dislocated at 12 months due to further trauma.

Conclusion: Recurrent instability following surgical stabilisation maybe due to soft-tissue failure. Soft-tissue failure can be subdivided into further trauma, inappropriate primary procedure, missed pathology and technical error. Cases within these subdivisions may be suitable for revision surgery using arthroscopic techniques.

Aim: To demonstrate that a multidisciplinary protocol reduces both in-patient stay and the need for out-patient physiotherapy following minimally invasive (MIS) uni-condylar knee replacements (UKR).

Methods: The data for hospital stay was collated for a consecutive group of primary UKR at our institution during 2002. We then compared this with a consecutive group of patients seen in a dedicated physiotherapist run clinic, with the provision of brochures and a “patient experience video”, with input from nurses, physiotherapists, anaesthetists, and surgeons, as well as time of expected discharge. The data was compared between informed (dedicated pre-operative assessment and patient video) and uninformed patients (standard pre-operative care).

Results: Total of 57 patients were initially assessed and compared with 81 patients after introduction of specific pre-op care pathway. Average hospital stay was reduced from 3.7 days to 2.1 days, with 60% going home within 24 hours.

Discussion: By changing the preconception of long hospital stays after arthroplasty ingrained in patients and staff we have reduced hospital stay significantly. Major factors contributing to this include the team approach, patient and ward staff education, perceptions of discharge and the inclusion of specific local anaesthetic techniques, and a minimally invasive approach. Delays in discharge include the geography of the region.