Long-term results of per-operative knee arthroscopy in confirming suitability for unicompartmental arthroplasty

BACKGROUND

Patient selection is key to the success of medial unicondylar knee arthroplasty (UKA). Progression of arthritis is the most common indication for revision surgery. Per-operative arthroscopy is a means of directly assessing the integrity of the lateral compartment. The aim of the study is to assess the long-term survivorship of UKA performed when per-operative arthroscopy is used as a final means of deciding whether to proceed with UKA.

METHODS

We used per-operative arthroscopy as a means to confirm suitability for UKA in a consecutive series of 279 Oxford medial UKA. Our series of UKA with per-operative arthroscopy (Group 1) was compared to all Oxford UKA (Group 2) and all UKA in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) (Group 3).

RESULTS

The 14-year cumulative percentage revision (CPR) was 18.5% (95% CI 12.7, 26.4) for group 1, 19.7% (95% CI 18.8, 20.6) for group 2, and 19.2% (95% CI 18.5, 19.8) for group 3. There was no statistically significant difference in the (CPR) for the entire period when group 1 was compared to groups 2 or 3. Progression of arthritis was least in Group 1 compared to groups 2 and 3; 3.6 versus 4.4 and 4.1% respectively. Following per-operative arthroscopy 21.6% (77/356) of knees underwent a change of surgical plan from UKA to TKA.

CONCLUSION

In our practice, which includes per-operative arthroscopy, we have identified a reduced risk of revision due to progression of arthritis but no difference in overall long-term implant survivorship.

Kinematically Aligned Oxford Unicompartmental Knee Arthroplasty Using the Microplasty Instrumentation System

This technical note demonstrates kinematically aligned Oxford unicompartmental knee arthroplasty using the Microplasty instrumentation system with custom-made devices. The medial joint line is evaluated preoperatively; if it is aligned and parallel with the lateral joint line, they are considered to comprise the coronal knee joint line (CJL). In this case, the coronal inclination of a spoon gauge inserted into the medial joint space indicates the CJL. Otherwise, an accessory spoon is inserted and connected to the medial spoon to refer to the posterior condylar line, which is considered the CJL. The tibial cutting block is then connected without changing the inclination of the spoon and the coronal tilt of the tibial extramedullary rod is adjusted, which is implemented with a custom-made ankle yoke. The remainder of the steps is then identical to the conventional Microplasty procedure. This technique can imitate the cutting line to the CJL, which might be considered ideal from mechanical and kinematic perspectives.

ANCA-associated vasculitis following Oxford-AstraZeneca COVID-19 vaccine in Brazil: Is there a causal relationship? A case report

This article presents a case of rapidly progressive glomerulonephritis following the Oxford-AstraZeneca COVID-19 vaccine in a female patient 58 years old. After 5 days, she presented fatigue, paleness, arthralgia on hands, knees, ankles, foamy urine, and elevated blood pressure. Exams showed serum creatinine of 2.2 mg/dL (baseline creatinine of 1.0 mg/dL). Urinalysis revealed hematuria, and her 24-h urinary protein excretion was 4.4 g. Additional exams showed hypercholesterolemia, severe anemia, and normal serum albumin. Testing of antineutrophil cytoplasmic antibodies anti-myeloperoxidase was positive at a titer of 1/80. Serum and urine protein electrophoresis and other exams showed no alterations. She was started on steroid pulse therapy after worsening kidney function, reaching serum creatinine of 3.3 mg/dL. A kidney biopsy revealed crescentic glomerulonephritis with glomerular sclerosis, fibrous crescents, interstitial fibrosis, and tubular atrophy. Induction therapy was given with intravenous cyclophosphamide 0.5 g/m² for 6-monthly pulses, followed by maintenance therapy with oral azathioprine at 2 mg/kg and prednisone tapering. The patient did not develop any complications during the induction therapy, and is currently on maintenance therapy with a serum creatinine of 1.87 mg/dL.

The Old Ashmolean Museum and Oxford's Seventeenth-Century Chymical Community: A Material Culture Approach To Laboratory Experiments

Towards the end of the seventeenth century, Oxford's chymical community came together in the Ashmolean Museum. Founded in 1683, the institution was part of Oxford University and home to the first official chair of chymistry in the country, with practical teaching directed by Robert Plot in the basement laboratory. The information at our disposal is scarce and Plot did not leave us detailed accounts of his laboratory work. However, a large assemblage of ceramic crucibles and distillation apparatus was recovered from the site where the laboratory once operated, an invaluable material perspective on the experimental agenda of one of the most important chymical laboratories in early modern Europe. The scientific analysis of the materials indicates that the work focused on technological innovation in the fields of glassmaking, specialised pottery, and zinc metallurgy, and shows how the laboratory kept close contact with some renowned artisan-entrepreneurs of the time. We argue that material culture offers an informative perspective on chymical practice in and beyond Oxford. The results provide fresh insight into the Old Ashmolean Museum, an institution that grew out of the Baconian spirit, where doing chymistry meant working at the intersection of artisanal and scholarly worlds.

Calipered kinematic alignment technique for implanting a Medial Oxford®: A technical note

This note describes a surgical technique to kinematically align a medial Oxford® UKA. Applying kinematic alignment principles is an alternative, personalised, physiological, and potentially clinically advantageous method for implanting the medial Oxford® UKA. Further investigations are needed to better define the reproducibility and clinical impact of this new surgical technique.

An Early Periprosthetic Fracture of a Cementless Oxford Unicompartmental Knee Arthroplasty: Risk Factors and Mitigation Strategies

Introduction:

The cementless Oxford partial knee arthroplasty is associated with low perioperative complications and good long-term survival rates. However, perioperative fractures remain a serious morbidity for patients.

Case Report:

This case report describes an early post-operative tibial periprosthetic fracture through the keel slot, which we believe may be contributed by the deep implant keel design and the presence of a narrow metaphysis in the Asian knee. The patient subsequently underwent a revision total knee replacement and fixation of the periprosthetic fracture.

Conclusion:

This paper discusses the ways to identify patients at high risk of developing periprosthetic fractures and to minimize such occurrences, including adopting a modified tibial preparation, doing precise saw cuts, and considering a cemented tibial implant.

Proximal tibial morphology and risk of posterior tibial cortex impingement in patients with AA-sized Oxford unicompartmental knee arthroplasty tibial implants

Background

In cases of Oxford unicompartmental knee arthroplasty (UKA), an increase in anteroposterior and medial-lateral length is usually disproportional when comparing AA and A-sized tibial components. Asynchronous increments may cause tibial keel impingement leading to complications.

Methods

Radiographic measurements were performed in five patients with AA-sized tibial implants. The posterior cortex of proximal tibia had two angles recorded as ∠ M1 and ∠ M2. The minimum distance between the tibial component keel and outer margin of the posterior tibial cortex (mDKC) was measured, and the correlation between the preoperative posterior slope angle (PSA), ∠ M1, and mDKC was analyzed.

Results

All patients showed an acceptable component positioning. Only one patient had an mDKC of < 4 mm that fulfilled the criteria for the posterior tibial cortex at risk. The patient had an increased PSA and ∠ M1 compared to other patients. A negative correlation was found between preoperative PSA and mDKC (r = − 0.935, p = 0.0193); and ∠ M1 and mDKC (r = − 0.969, p = 0.0032). However, no stem tip pain, periprosthetic fracture, or component loosening were observed.

Conclusions

The distance between the tibial keel and posterior tibial cortex was reduced in AA-sized patients with a large PSA and ∠M1; therefore, the risk of the tibial cortex injury should be considered.

Five-year results from an independent series

BACKGROUND

Unicompartmental knee replacement (UKR) is a common treatment option for patients with advanced medial compartment knee arthritis. The Oxford UKR (OUKR) is the most commonly used implant for partial knee replacement. A cementless Oxford prosthesis was introduced in 2004 aiming to reduce the revision rate by potentially reducing radiolucencies as well as errors of cementation associated with the cemented prosthesis. Whilst results from the designer centre have been reported, there is little independent clinical evidence of outcomes. The aim of this study was to evaluate the survival of the cementless OUKR in a single surgeon series at an independent centre and to assess clinical and radiographic outcomes.

METHODS

All patients who received a cementless medial OUKR and had a minimum of five-year follow-up were included in the series. The Oxford knee score was used to evaluate patient outcomes at five years postoperatively. Survival rates, complications and evidence of radiolucencies on plain radiographs were also reviewed.

RESULTS

One hundred and fifty-eight cementless medial OUKR were implanted in 126 patients. Three patients died and four knees were revised. The five-year survival was 97.4% and the median Oxford knee score was 43 at five years postoperatively. No Complete radiolucent lines were observed on radiographs at one year. Four tibial components subsided.

CONCLUSIONS

This independent series shows that low revision rates and excellent results can be achieved with the use of the cementless OUKR at five years. Early subsidence of the tibial component, which is specific to the cementless prosthesis, warrants further investigation.

[Consideration of Occupational Diversity via Academia through Studying Abroad in the UK]

Studying abroad may prove an attractive opportunity for young Japanese scientists, as it would allow them to broaden their perspectives regarding occupational diversity as a scientist. This is the first observation I made after studying abroad at the University of Oxford for two and a half years as a postdoctoral fellow. Many young scientists in the UK have got occupations not only in academia or in manufacturing industries, but also in various other business fields. Their occupational diversity seems to be considerably wider than that found among young Japanese scientists. The second feature I observed was related to my new lifestyle in the UK, which included the practice of research. It was notably different from my experiences in Japan, and it made me reconsider how to conduct my research in a more efficient manner. During my stay in the UK, I was able to identify the significance of spending time in a different culture by avoiding contact with Japanese culture as much as I could. In this essay, I introduce the details of my process of departing for the UK and my life in Oxford; it is my hope that this information will be useful for young Japanese scientists in contemplating their life plans.

Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty: Multicenter Analysis of 67 Bearing Dislocations

BACKGROUND

This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases.

METHODS

We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort.

RESULTS

There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs.

CONCLUSION

Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases.

LEVEL OF EVIDENCE

IV, Case series.

How computational chemistry develops: a tribute to Peter Goodford

This editorial discusses the foundation of aspects of computational chemistry and is a tribute to Peter Goodford, one of those founders, who recently passed away. Several colleagues describe Professor Goodford's work and the person himself.

Asymptomatic population reference values for three knee patient-reported outcomes measures: evaluation of an electronic data collection system and implications for future international, multi-centre cohort studies

OBJECTIVES

The aim was to assess whether the Knee Society Score, Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were comparable in asymptomatic, healthy, individuals of different age, gender and ethnicity, across two remote continents. The purpose of this study was to establish normal population values for these scores using an electronic data collection system.

HYPOTHESIS

There is no difference in clinical knee scores in an asymptomatic population when comparing age, gender and ethnicity, across two remote continents.

METHODS

312 Australian and 314 Canadian citizens, aged 18-94 years, with no active knee pain, injury or pathology in the ipsilateral knee corresponding to their dominant arm, were evaluated. A knee examination was performed and participants completed an electronically administered questionnaire covering the subjective components of the knee scores. The cohorts were age- and gender-matched. Chi-square tests, Fisher's exact test and Poisson regression models were used where appropriate, to investigate the association between knee scores, age, gender, ethnicity and nationality.

RESULTS

There was a significant inverse relationship between age and all assessment tools. OKS recorded a significant difference between gender with females scoring on average 1% lower score. There was no significant difference between international cohorts when comparing all assessment tools.

CONCLUSIONS

An electronic, multi-centre data collection system can be effectively utilized to assess remote international cohorts. Differences in gender, age, ethnicity and nationality should be taken into consideration when using knee scores to compare to pathological patient scores. This study has established an electronic, normal control group for future studies using the Knee society, Oxford, and KOOS knee scores.

LEVEL OF EVIDENCE

Diagnostic Level II.

Eight Hundred Twenty-Five Medial Mobile-Bearing Unicompartmental Knee Arthroplasties: The First 10-Year US Multi-Center Survival Analysis

BACKGROUND

FDA approval for the Oxford phase III device was approved for use in the United States in 2004. This study seeks to provide the first long-term, large patient sample size, Oxford phase III multi-site survivorship study in the United States, investigating patient reported outcomes of pain and function, while also providing an in-depth analysis of causes for revision, and finally addressing recent advancements that can help aid the unicompartmental knee arthroplasty (UKA) process and further improve partial knee survivorship.

METHODS

Between July 2004 and December 2006, 5 surgeons from around the United States performed medial UKA through the minimally invasive surgical approach, on 825 knees in 695 patients. This was a consecutive series of primary UKAs using the phase III mobile bearing; cemented Oxford Knee (Zimmer Biomet, Warsaw, IN), implanted utilizing phase III instrumentation. UKA survivorship considered all revisions as the end point. Implant survivorship eliminated revisions at which the original Oxford implant was determined to be well fixated and functional intra-operatively.

RESULTS

A total of 93 knees were revised in this study. Mean follow-up was 9.7 years (6-12). Implant survivorship at year 10 was 90% (confidence interval 2.7%). UKA survivorship at year 10 was 85% (confidence interval 3.8%). Average preoperative American Knee Society Score (knee score) was 49 and rose to 90 postoperatively (standard deviations 16 and 18, respectively). Average preoperative American Knee Society Score (function score) was 55 and rose to 77 postoperatively (standard deviations 15 and 28, respectively).

CONCLUSION

This was the first large-scale, 10-year, multi-site follow-up of the Oxford mobile-bearing medial UKA undertaken in the United States, displaying good survivorship and excellent patient outcomes.

An international, multicenter cohort study comparing 6 shoulder clinical scores in an asymptomatic population

HYPOTHESIS

The study purpose was to assess 6 shoulder patient-reported outcome measure (PROM) values in asymptomatic, healthy, pathology-free individuals. We hypothesized that there would be no difference in PROM values in pathology-free individuals when considering sex, age, ethnicity, and geographical location.

METHODS

Electronic questionnaires were completed by 635 individuals (323 Australians and 312 Canadians) without dominant shoulder pathology for the American Shoulder and Elbow Surgeons (ASES) shoulder score; Constant-Murley Shoulder Score (CSS); Oxford Shoulder Score (OSS); University of California, Los Angeles (UCLA) shoulder score; Shoulder Pain and Disability Index (SPADI); and Stanmore Percentage of Normal Shoulder Assessment (SPONSA). Shoulder range of motion and strength were assessed.

RESULTS

No difference was identified between subjective-only and subjective-objective PROMs. Handedness and a current elbow or wrist problem were not associated with differences in PROM values. Poorer PROM values were associated with a history of an inactive shoulder problem and increasing age. Female participants tended to report similar or poorer PROM scores. No significant difference was found between ethnicities. Geographical location was associated with differences in the ASES shoulder score, UCLA shoulder score, and SPADI but not the CSS, SPONSA, and OSS.

CONCLUSIONS

Differences in sex, age, and geographical location will affect PROM shoulder scores in pathology-free individuals and should be taken into consideration when PROMs are being used to compare patient outcomes. This study has established normative values for the ASES shoulder score, CSS, OSS, UCLA shoulder score, SPADI, and SPONSA. Future studies assessing a pathologic patient cohort should perform comparisons against a sex- and age-matched control cohort, ideally sourced from the same geographical location.

The Oxford knee score and its subscales do not exhibit a ceiling or a floor effect in knee arthroplasty patients: an analysis of the National Health Service PROMs data set

PURPOSE

In this study, we examined whether the OKS demonstrated a floor or a ceiling effect when used to measure the outcome of knee replacement surgery in a large national cohort.

METHODS

NHS PROMs database, containing pre- to 6 month post-operative OKS on 72,154 patients, mean age 69 (SD 9.4), undergoing knee replacement surgery, was examined to establish the proportion of patients achieving top or bottom OKS values pre- and post-operatively.

RESULTS

Pre-operatively, none of patients achieved the maximum/'best' (48) and minimum (0) scores. Post-operatively, no patients (0 %) achieved the minimum/'worst' score, but the percentage achieving the maximum score increased to 2.7 %. Subgroup analyses demonstrated that the highest post-operative overall ceiling percentage was 3 %, in a subgroup of patients between 60 and 79 years of age and 13.7 % in a group of patients who had a pre-operative OKS above 41. Furthermore, 10.8 % of patients achieved the top post-operative OKS-PCS and 4.7 % top post-operative OKS-FCS.

CONCLUSION

Based on NHS PROMs data, the OKS does not exhibit a ceiling or floor effect overall, or for both its pain and function subscales, and remains a valid measure of outcomes for patients undergoing TKA.

LEVEL OF EVIDENCE

Large-scale retrospective observations study, Level II.

Superior femoral component alignment can be achieved with Oxford microplasty instrumentation after minimally invasive unicompartmental knee arthroplasty

PURPOSE

Oxford microplasty (MP) instrumentation has been developed to facilitate the reproducible and consistent performance of minimally invasive unicompartmental knee arthroplasty (MI-UKA) operation. The aim of this study was to compare the clinical and radiographic results of two groups of patients implanted using either a conventional instrumentation technique or an MP technique.

METHODS

A prospective cohort study of 108 knees in 108 patients who underwent an MI-UKA procedure using either conventionally instrumented UKA (CI-UKA) (52 knees of 52 patients) or MP-assisted UKA (MP-UKA) (56 knees of 56 patients). The clinical assessment included the Oxford Knee Score (OKS), the Knee Society Score (KSS), a visual analogue scale (VAS) for pain, and range of motion (ROM). Complications were also recorded.

RESULTS

No significant differences were observed between the two groups regarding OKS, KSS, VAS, and ROM. There were also no significant differences in terms of mechanical limb alignment and tibia implant alignment. However, the MP-UKA group showed significantly more accurate positioning of the femoral component than the CI-UKA group. Additionally, the MP-UKA group had more femoral prostheses implanted in the "satisfactory" range and fewer "outliers" than the CI-UKA group. No significant difference in complications was noted between the two groups.

CONCLUSION

This study suggested that compared with CI-UKA, MP-UKA provides significant improvements in increasing the accuracy of sagittal and coronal implantation of the femoral component and in reducing the numbers of outliers for femoral prosthetic alignment. It is advocated that the MP system should be considered when MI-UKA is performed.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

The comparison of anterior knee pain in severe and non severe arthritis of the lateral facet of the patella following a mobile bearing unicompartmental knee arthroplasty

In the past, medial osteoarthritis (OA) knee with symptomatic patellofemoral (PF) arthritis has not been recommended for a unicompartmental knee arthroplasty (UKA). However, recent studies have reported that UKA has shown good results in patients with medial OA of the knee, including those with PF arthritis. The purpose of this study is to compare the results between patients with medial OA knees; those with severe arthritis of the lateral facet of the patella and patients without severe arthritis of the lateral facet of the patella following mobile bearing UKA. We have prospectively evaluated 104 patients (114 knees) who had undergone an Oxford mobile bearing UKA. The mean follow-up was 19.05 months (range 12.30–29.70 months). The patients were divided into two groups: group I consisted of eighty patients (88 knees) who did not have severe arthritis of the lateral facet (Outerbridge grade 0–2) and group II had twenty-four patients (26 knees) who had severe arthritis of the lateral facet (Outerbridge grade 3, 4). We recorded the incidence of anterior knee pain, knee scores, pain scores, and functional scores in comparison of the two groups. The visual analog scale (VAS) and incidence of post-operative anterior knee pain had not shown any significant differences. The VAS for post-operative anterior knee pain was 0.11 (SD 0.56, range 0–3 point) versus 0.12 (SD 0.59, range 0–3 point) for group I and group II patients, respectively (P = 0.98). The incidence of post-operative anterior knee pain was 4.5 versus 3.8 % for group I and group II patients, respectively (P = 0.88). The pain scores and functional scores had not exhibited any differences. However, the knee scores of patients with severe arthritis of the lateral facet of the patella was worse than those seen in patients without severe arthritis of the lateral facet of the patella with a statistical significance. It was scored as 96.78 (SD 4.56, range 85–100) versus 94.43 (SD 4.50, range 81–100) for group I and group II patients, respectively (P = 0.02). Anterior knee pain, pain scores, and functional scores were not different between the two groups following a medial Oxford UKA. However, the knee scores of patients with severe arthritis of the lateral facet were worse than those in patients without severe arthritis of the lateral facet of the patella.

Extracapillary proliferation and arteriolar hyalinosis are associated with long-term kidney survival in IgA nephropathy

BACKGROUND

The Oxford classification of IgA nephropathy consists of four markers as prognosticators. We retrospectively examined the relevance of extracapillary proliferation involving cellular and fibrocellular crescents (Ex) and arteriolar hyalinosis (A) on the long-term outcome of renal function.

METHODS

A total of 314 Japanese patients who were diagnosed with IgA nephropathy, with 12 months or more of follow-up period were included in this study. A total of 186 patients were with UP ≥ 0.5 g/day. Patients with diabetes mellitus or severe kidney injury (eGFR < 30 ml/min/1.73 m(2)) were excluded. The presence of Ex and A were scored 0 in the absence, and 1 in the presence, of each lesion. The end point was determined as a 50 % reduction in initial eGFR or end-stage renal disease defined as eGFR < 15 ml/min/1.73 m(2).

RESULTS

In univariate analyses, the kidney survival rate was significantly lower in patients with Ex1 and A1 if UP ≥ 0.5 g/day. In the patients with UP < 0.5/day, none of the clinical and pathological parameters was determined as a risk factor. In the multivariate model including pathological parameters, Ex1 and A1 were independent risk factors for renal outcome if UP ≥ 0.5 g/day. In those patients treated with RAS-blocker or treated before introduction of methylprednisolone pulse therapy, Ex was the only independent risk factor. In multivariate analysis including clinical parameters, eGFR alone was a risk factor, due to strong correlation with other parameters.

CONCLUSION

Ex and A would be associated with the renal outcome of the patients with UP ≥ 0.5 g/day.

Revision of unicompartmental knee arthroplasty versus primary total knee arthroplasty

The risk of revision following unicompartmental arthroplasty (UKA) is greater compared with primary total knee arthroplasty (TKA). Some surgeons report that UKA revision is straightforward with outcomes comparable to TKA. We reviewed all Oxford medial UKAs and TKAs performed at our institution over a five year period. Patient reported outcomes were compared between revised UKAs, successful UKAs and primary TKAs. Out of 546 Oxford medial UKAs, twenty-nine (5.3%) were revised at a mean of 25months. The commonest indications for revision were aseptic loosening and progression of osteoarthritis. Ten patients (34%) required augments, stemmed implants or bone grafts. Outcomes following revision were poorer than those following successful UKA and primary TKA, and were a consequence of poor pre-operative function rather than the complexity of surgery.

Mobile-bearing unicondylar knee arthroplasty: the Oxford experience

With the recent increase in medial unicompartmental arthroplasty, this article reviews the design history, indications, results, and modern technique for the implantation of the Oxford mobile-bearing unicompartmental arthroplasty. The article also discusses how the indications for the Oxford differ from the historical indications for medial unicompartmental arthroplasty and supports this paradigm shift with review of the recent data. A detailed series of surgical pearls is also presented to help surgeons with the surgical nuances of the Oxford partial knee.

Oxford shoulder score in a normal population

Background:

The function of the asymptomatic normal shoulder may differ according to gender and could also deteriorate with age. This may result in a disparity in the normal Oxford shoulder score (OSS) according to these variables. If a difference were to exist an adjusted OSS, for age and gender, could be calculated from the raw score using the expected normal score.

Aim:

The aim of this study was to define a normal OSS in an asymptomatic population according to age and gender.

Materials and Methods:

During the study period 202 patients aged from 20 years to 99 years with subjectively asymptomatic shoulders completed an OSS. These patients presented to the study center during a 1 week period for management of disorders out with their shoulder girdle. Patients with a known prior shoulder pathology, injury, or polyarthropathy were excluded.

Results:

The mean OSS varied according age and gender. There was a significant correlation between age and the OSS, with an increasing score (worse) being associated with older age (r = 0.62, P < 0.0001). The mean OSS for females was 18.8 (12-42, SD 5.4) and for males was 16.3 (12-30, SD 4.5), this difference was significant (P = 0.0001). We propose that a normalized OSS could be calculated as a percentage by the using the expected normal for that patient's age and gender as demonstrated in this study ((raw score/normal score) × 100).

Conclusion:

Our study provides normal data for an urban population presenting to orthopedic services and allows for a relative OSS to be calculated from the raw score.