Distal femoral osteotomy is an established successful procedure which can delay the progression of arthritis and the need for knee arthroplasty. The surgery, however, is complex and lengthy and consequently it is generally the preserve of highly experienced specialists and thus not widely offered. Patient specific instrumentation is known to reduce procedural complexity, time, and surgeons’ anxiety levels1 in proximal tibial osteotomy procedures. This study evaluated a novel patient specific distal femoral osteotomy procedure (Orthoscape, Bath, UK) which aimed to use custom-made implants and instrumentation to provide a precision correction while also simplifying the procedure so that more surgeons would be comfortable offering the procedure. Three patients (n=3) with early-stage knee arthritis presented with valgus malalignment, the source of which was predominantly located within the distal femur, rather than intraarticular. Using conventional techniques and instrumentation, distal femoral knee osteotomy cases typically require 1.5–2 hours surgery time. The use of bi-planar osteotomy cuts have been shown to improve intraoperative stability as well as bone healing times2. This normally also increases surgical complexity; however, multiple cutting slots can be easily incorporated into patient specific instrumentation.Abstract
Background
Presenting problem
We aimed (1) to determine the factors which influence outcome after surgery for CES and (2) to study CES MRI measurements. 56 patients with evidence of a sphincteric disturbance who underwent urgent surgery (1994-2002) were identified and invited to clinic. 31 MRIs were available for analysis and randomised with 19 MRIs of patients undergoing discectomy for persistent radiculopathy. Observers estimated the percentage of spinal canal compromise and indicated whether they thought the scan findings could produce CES and whether the discs looked degenerate. Measurements were repeated after two weeks. (1) 42 patients attended (mean follow up 60 months; range 25–114). Mean age at onset was 41 years (range 24–67). 26 patients were operated on within 48 hours of onset. Acute onset of sphincteric symptoms and the time to operation did not influence the outcomes. Leg weakness at onset persisted in a significant number at follow-up (p<0.005). Bowel disturbance at presentation was associated with sexual problems (<0.005) at follow-up. Urinary disturbance at presentation did not affect the outcomes. The 13 patients who failed their post-operative trial without catheter had worse outcomes. The SF36 scores at follow-up were reduced compared to age-matched norms in the population. The mean ODI was 29, LBOS 42 and VAS 4.5. (2) No significant correlations were found between MRI canal compromise and clinical outcome. There was moderate to substantial agreement for intra- and inter-observer reproducibility. Due to small numbers we cannot make the conclusion that delay to surgery influences outcome. Based on the SF36, LBOS and ODI scores, patients who have had CES do not return to a normal status. Using MRI alone, the correct identification of CES has sensitivity 68%, specificity 80% positive predictive value 84% and negative predictive value 60%. CES occurs in degenerate discs.Conclusions
At follow up significantly more females had urinary incontinence (p<
0.001) and bowel disturbance (p<
0.05), higher VAS scores (p<
0.05) and lower SF36 Pain and Energy scores (p<
0.05) than males. Urinary disturbance at presentation did not affect the outcomes. Bowel disturbance at presentation was associated with sexual problems (<
0.005) and abnormal rectal tone (p<
0.05) at follow up. Objective reduced perianal sensation at onset persisted in a significant number at follow up (21/32 patients; p<
0.05) as did leg weakness (14/23; p<
0.005). There was a weak association between delay to operation and bowel disturbance (p<
0.05) at follow up. Eight patients had faecal soiling and faecal incontinence at follow up and this was associated with sudden onset of symptoms, initial abnormal rectal tone and time to operation (p<
0.05). The SF36 scores at follow up were reduced compared to age matched norms in the population. The mean ODI was 29, LBOS 42 and VAS 4.5.