Aims

The lack of disease-modifying treatments for osteoarthritis (OA) is linked to a shortage of suitable biomarkers. This study combines multi-molecule synovial fluid analysis with machine learning to produce an accurate diagnostic biomarker model for end-stage knee OA (esOA).

Carpal tunnel syndrome (CTS) is said to be a condition of middle-aged women. Our experience is that it more commonly occurs in older people and also in a younger working population. The aim of this study is to describe the epidemiology of CTS requiring carpal tunnel decompression (CTD).

Over a 10.5 year period 3073 CTD were performed on 2309 patients aged 15 – 93 years. This included all public, private and ACC funded cases in our region. During this period we had no restriction to access to CTD as all publicly funded cases were performed under local anaesthetic in a day surgery unit. Neurophysiological studies were performed pre-operatively by the same neurophysiologist. Population data from the national census (2006) was used to calculate the annual incidence of patients requiring CTD for each 5 year age band.

There were 1418 females (61.4%) and 891 males (38.6 %). In contrast females comprised 116 of 306 (37.8%) patients who had their surgery funded by ACC. The mean age at surgery was 45 years for ACC cases compared with 56 years for non-ACC funded cases. The incidence of males having surgery funded by ACC was 1.7 times higher than females.

There was a biphasic pattern in females with an incidence of 3.0/1000 at age 50–54 years, and a second higher peak of 3.1 to 3.4/1000 from 70 to 5 years. Males had a linear increase in incidence peaking at 3.1/1000 for age 65–69 years declining slightly to 2.8/1000 for age 70–85 years. The incidence was significantly higher in females than males overall (1.8 v 1.1/1000) and in patients under 65 years (1.4 v 0.8/1000). In patients over 65 years there was no significant difference in incidence (female 2.8, male 2.5/1000).

Within our region, the incidence of surgically treated carpal tunnel syndrome increases with age. The highest rates are seen over the age of 70 in women and 65 years in men with no significant difference in rates between men or women over 65 years.

Introduction: Coding systems are important for epidemiology, research, audit, activity analysis and now remuneration. There have been concerns that the existing coding systems do not represent foot and ankle activity accurately.

Materials and Methods: The senior author’s logbook was analysed for 2 years. Each operation descriptor was recorded. A “simple descriptor” described an operation of one component (“scarf osteotomy”). A “multiple descriptor” described multiple instances of one component (“bilateral scarf osteotomy”). A “compound descriptor” described a procedure made up of more than one component (“scarf osteotomy and 2nd toe straightening”). We encoded the logbook using OPCS4.5 and the RCSED Electronic Logbook. We assessed whether simple descriptors could be coded unambiguously (ie there was a one-to-one relationship between descriptor and code so that distinct procedures could be identified) and whether compound descriptors contained ambiguous codes. We also considered whether the overall procedure was adequately summarised by the tabulated codes. Codes were converted to the HRG4 and BUPA payment codes and referenced to chevron osteotomy.

Results: There were 513 procedures with 157 different descriptors (3.27 cases/descriptor, compared with 4.44 in upper limb and 7.69 in lower limb). Fifty-four descriptors (321 patients) were simple, 18 (52 patients) were multiple and 85 (140 patients) were compound. Using OPCS, 57.4% of simple descriptors (46.1% of patients) were ambiguous, as were 82.4% of compound descriptors (85.7% of patients). In 27.1% of descriptors (33.6% of patients) the tabulated codes did not give the overall procedure clearly. Using the eLogbook, 48.1% of simple descriptors (25.2% of patients) and 74.1% of complex descriptors (70.7% of patients) were ambiguous and in 30.6% of descriptors (37.1% of patients) the codes did not summarise the operation well. Most remuneration compared reasonably with chevron osteotomy, with some idiosyncrasies. Overall remuneration was lower than procedures of comparable complexity in other specialties.

Introduction Vertebroplasty (VP), where vertebral bodies are injected with polymethylmethacrylate (PMMA) cement, is used to treat various spinal lesions. More recently VP has been used for augmenting osteoporotic vertebral bodies that have fractured or are at risk of fracture. Although the complication rate for VP is low, thermal damage caused by the exothermic curing of PMMA has been implicated.

The aim of this series of experiments was to measure the temperatures reached during VP using a sheep model. The cement volume effect and inter cement differences were assessed. Spinal cord monitoring was undertaken to monitor spinal cord function during this procedure to validate this for clinical use.

Methods In the in vivo experiment each of the lumbar vertebral bodies of 10 sheep were injected with one of two cements (Simplex & Vertebroplastic) and one of two volumes (3.0ml or 6.0ml). This was undertaken through an open approach in the lumbar vertebrae. While performing the in vivo experimental studies 6 of the sheep were concurrently monitored using epidural Motor Evoked Potentials (MEP’s).

Results There was a significant increase in the temperature at the bone cement interface. The mean peak temperature at the bone-cement interface was 49.5 C (3.0ml Simplex); 61.47 C (6.0ml Simplex); 42.1 C (DePuy 3ml) and 47.2 (DePuy 6ml).

Spinal cord monitoring showed that when PMMA was injected into the correct location within the vertebral body there was no change in amplitude of the evoked potentials. When significant leakage of PMMA occurred, there was a decrease in amplitude of MEP’s.

Discussion In this sheep model, using cement volumes similar to those used in human clinical practice, we were able to monitor temperature changes within the vertebral body at the bone cement interface. The temperature of the bone cement interface reached temperatures that are known to cause tissue necrosis.

Using epidural monitoring we were able to show that when PMMA is injected into the correct location within the vertebral body there is no change in amplitude of MEP’s.

Percutaneous vertebroplasty (PVP), where vertebral bodies are injected with polymethylmethacrylate (PMMA) cement, is used to treat various spinal lesions. Although the complication rate for PVP is low, thermal damage caused by the exothermic curing of PMMA has been implicated.

This study was to measure the temperatures reached during PVP as PMMA cures as well as assessing the cement volume effect and inter cement differences. Validating spinal cord monitoring during PVP was also undertaken.

In the in vivo experiment each of the lumbar vertebral bodies of 10 sheep were injected with one of two cements and one of two volumes. Thermocouple monitoring was undertaken at the bone cement interface. While undertaking the in vivo experimental studies 6 sheep underwent epidural monitoring using Motor Evoked Potentials (MEPs).

The mean peak temperature at the bone-cement interface was 49.5 C (3.0ml Simplex); 61.47 C (6.0ml Simplex); 42.1 C (DePuy 3ml) and 47.2 (DePuy 6ml). Spinal cord monitoring showed that when cement was injected into the correct location within the trabeculae of the vertebral body no change in amplitude monitoring was noted. When leakage occurred, deliberate or unintended, amplitude changes were noted.

Using cement volumes similar to those used in human clinical practice in a sheep model we were able to monitor temperature changes. The temperature of the bone cement interface reached temperatures that are known to cause tissue necrosis. Using epidural monitoring we were able to detect leakage of cement during injection.

The aim of this study was to prospectively audit the results of carpal tunnel decompression using a subjective patient derived outcome score (modified Boston Symptom Severity Score) and to examine the relationship between symptom severity scores and nerve conduction studies.

Prospective cohort study of all patients undergoing open carpal tunnel decompression at Dunedin Hospital over a 13-month period from December 2003 – January 2005. Demographic details collected included age, sex, duration of symptoms, diabetes, occupation and ACC status. Pre-operative investigations consisted of nerve conduction studies and a modified version of the Boston Symptom Severity Score developed for this study. Symptom severity scores were reassessed six months post-operatively.

One hundred and ten patients participated in the study. Mean pre-operative Boston Symptom Severity Score was 3.35 (1= normal, 5=severe). Post-operatively this improved to mean 1.66, median 1.45. Ninety three percent of patients were “very satisfied” or “satisfied” with their results. Age and duration of symptoms were not significant predictors of poor outcome.

The majority of patients undergoing carpal tunnel decompression were satisfied with the outcome and had excellent or good outcomes as determined by symptom severity score. The use of preoperative nerve conduction studies help in diagnosis and prognosis.

Introduction and Aims: It has been suggested that elderly patients have poorer outcomes following carpal tunnel decompression than younger patients, especially if there is severe compression. The purpose of this study was to determine the outcomes of carpal tunnel decompression in the elderly patient and whether the outcome could be predicted from pre-operative nerve conduction studies.

Method: A retrospective study of all patients over 70 years who had a carpal tunnel release over a three-year period at Dunedin Hospital, with a minimum one-year follow-up. Pre-operative nerve conduction studies were graded from one to six according to severity. Patients were followed up by postal questionnaire (Boston carpal tunnel symptom severity score) and telephone follow-up.

Results: 109 procedures were performed in 96 patients. Eight patients had died, two excluded (one with Motor Neurone disease and one acute CTS following fracture) and five were demented and unable to fill out the questionnaire. Eighty-one patients with 92 wrists were available for review. Mean age was 78.6 years. Eighty percent had marked to severe neurophysiological changes (Grade 4–6). Post-operatively, the median Boston score was 1.27 with 84% having a Boston score of < 2.0. Patients were satisfied with the result in 94.6% of procedures. There was a positive correlation between nerve conduction grade and post-operative Boston Score (p=0.042).

Conclusion: Despite nerve conduction studies consistent with marked to severe compression, elderly patients have low symptom severity scores following carpal tunnel decompression and a high rate of satisfaction. Carpal tunnel release in patients over 70 years of age is justified and usually associated with a good outcome.

The aim of this study was to determine the outcome of carpal tunnel decompression in elderly patients and whether this can be predicted by the severity of pre-operative nerve conduction studies.

A retrospective study was undertaken of all patients over 70 years who had carpal tunnel release (CTR) at Dunedin Hospital between April 1999 and April 2002 with a minimum one year follow up. A grading system for pre-operative nerve conduction studies (NCS) was formulated which scored patients from 1 to 6 according to severity. Patients were followed up by postal questionnaire (Boston Carpal Tunnel Score) with telephone follow up of non-responders.

There were 105 CTR procedures performed in 96 patients. Median pre-operative NCS Score was 4 with 47% scoring 5 or 6. 4 Patients had died. Post-operative symptom severity scores were low and the majority of patients were very satisfied with the results of surgery.

Despite nerve conduction studies consistent with severe median nerve compression, patients had low postoperative symptom severity scores and overall were very satisfied. Carpal tunnel release in patients over 70 years of age is justified and associated with good outcome.