Introduction: The importance of soft tissue balance in total knee arthroplasty (TKA) has been documented, and several authors have documented operative procedure of soft tissue release for soft tissue balancing. However, the quantity of change of soft tissue balance in each procedure has not been reported in detail, and the importance of each procedure of soft tissue release has not been well argued. This study is a quantitative evaluation of the effect of soft tissue release on soft tissue balance in TKA. Materials and methods: Forty-five varus knees in 42 patients with a preoperative femorotibial angle (FTA) of more than 180°underwent TKAs from 1996 to 2000, and these knees were evaluated in this study. The mean age of the subject was 70.1 years (from 33 to 87 years), including 5 knees in male and 40 knees in female. The extension and flexion gap of the knee joint was measured by the instrument applying the force of the moment of 50kg& #65381;cm to each medial and lateral joints. We decided the procedure of soft tissue balancing as follows and the extension and flexion gap were measured in each steps. The procedure were 1) exposure of posterior medial aspects of the tibia with release of the attachment of semimembranosis, 2) removal of osteophytes from the medial distal femur and proximal tibia, 3) resection of the posterior cruciate ligament (if necessary), 4) release of the superficial medial collateral ligament (MCL), 5) resection of the superficial MCL (if necessary). Results: The results of the change of the extension and flexion gap in each procedure were shown as below. Final gap was calculated as the difference against medial extension gaps. Procedure: The change of extension gap The change of flexion gap medial lateral medial lateral 1) (n=45) 1.2 ± 1.4 1.2 ± 1.2 1.9 ± 2.2 1.7 ± 2.6 2) (n=36) 1.9 ± 2.5 0.7 ± 1.2 1.7 ± 1.6 1.3 ± 2.0 3) (n=19) 1.8 ± 1.5 1.9 ± 1.8 2.7 ± 2.0 2.9 ± 2.2 4) (n=18) 2.0 ± 1.9 0.3 ± 0.5 2.4 ± 1.7 0.9 ± 1.1 5) (n=4) 2.8 ± 2.3 0.4 ± 0.8 4.1 ± 1.5 1.5 ± 1.4 Final gap 0 3.4 ± 2.6 0.5 ± 3.1 3.1 ± 3.4. Discussion: The change of soft tissue balance in each soft tissue procedure in TKA was evaluated quantitatively in this study. The amount of the changes in each steps were few and differed with cases. The procedure for medial osteophytes and MCL had a tendency of efficacy to medial tightness against lateral in knees with varus deformity

Total knee arthroplasty (TKA) is a common orthopaedic procedure. Traditionally the surgeon, based on experience, releases the medial structures in knees with varus deformity and lateral structures in knees with valgus deformity until subjectively they feel that they have achieved the intended alignment. The hypothesis for this study was that deformed knees do not routinely require releases to achieve an aligned lower limb in TKA. A single surgeon consecutive cohort of 74 patients undergoing computer navigated TKA was examined. The mechanical axes were taken as the references for distal femoral and proximal tibial cuts. The trans-epicondylar axis was taken as the reference for frontal femoral and posterior condylar cuts. A soft tissue release was undertaken after the bony cuts had been made if the mechanical femoro-tibial (MFT) angle in extension did not come to within 2° of neutral as shown by computer readings. The post-operative alignment was recorded on the navigation system and also analysed with hip-knee-ankle (HKA) radiographs. The range of pre-operative deformities on HKA radiographs was 15° varus to 27° valgus with a mean of 5° varus (SD 7.4°). Only two patients required a medial release. None of the patients required a lateral release. The post implant navigation value was within 2° of neutral in all cases. Post-operative HKA radiographs was available for 71 patients. The mean MFT angle from radiographs was 0.1° valgus (SD 2.1°). The range was from 6° varus to 7° valgus but only six patients (8.5%) were outside the ±3° range. The kinematic analysis also showed it to be within 2 degrees of neutral throughout the flexion making sure it is well balanced in 88% cases. This series has shown that over 90% of patients had limbs aligned appropriately without the need for routine soft tissue releases. The use of computer assisted bone cuts leads to a low level of collateral release in TKA

113 consecutive patients with soft tissue sarcoma treated by excision and reconstructive flaps were studied to assess the risk of complications and to compare local tumour control with those in whom primary wound closure was possible. Minimum follow-up was 24 months and mean age was 55 years (16–95). The sarcoma was located in the lower extremity in 83 and upper extremity 30 patients. Significant wound complications developed in 37 patients (33%). The most common complications were wound infections or partial necrosis occurring in 16% (18/113) and 13% (15/113) respectively. Complete flap necrosis requiring flap removal occurred in 6 patients (5%). Three patients (2.3%) required amputation as a result of complications. Significant risk factors for development of wound complications include location of tumour in the lower limb compared to upper limb (relative risk 2.3, p=0.02) and use of pre-operative radiotherapy compared to no or post-operative radiotherapy (relative risk 2.05, p=0.02). There was no difference in rates of complications in patients with free or pedicled flaps, tumours < or > 5cm, distal or proximal location of tumour. The rates of negative excision margins (80%) and wound complications in patients who required reconstructive flaps were not different from that for the other patients treated at our centre who did not require reconstructive flaps. The use of soft tissue reconstructive flaps did not reduce the risk of positive excision margins or the rates of wound complications. The risk of amputation secondary to flap complication or failure is low

Introduction. The incidence of dislocation after total hip arthroplasty (THA) was reported to be 0.5 to 10% in primary THA and 10 to 25 % in revision THA. The main causes of instability after THA were reported to be implant malalignment and inappropriate soft tissue tension. However, there was no study about quantitative data of soft tissue tension of unstable THA. The purpose of this study is to clarify the features of soft tissue tension of unstable THA in comparison to stable THA. Methods. The subjects were 15 patients with 15 THAs who had developed recurrent dislocation after primary THA. Thirty four patients with 37 THAs who developed no dislocation for one year after surgery were recruited as a stable THA group. In both group, all THAs were performed through posterolateral approach. In order to assess the soft tissue tension of THA, we recorded antero-posterior radiographs of the hips while applying distal traction to the leg with traction forces of 20?, 30%, 40% of body weight (BW). The distance of separation of the head and the cup after traction was measured under correction of magnification. Nine of 15 THAs in the unstable THA group and 32 of 37 THAs in the stable THA group were unilateral involvement. In the hips with unilateral involvement, the femoral offset difference between the healthy hip and the reconstructed hip were evaluated. Statistical analysis was performed with χ2 testand Mann-Whitney U test, and statistical significance was set at P<0.05. Results and Discussion. The average separation distance of the head and the cup was 5.2 ± 3.4mm (SD) at 40%BW, 4.3±3.2mm at 30%BW, and 3.2±2.8mm at 20%BW in the unstable THA group. The average separation distance of the head and the cup was 1.4±1.5mm at 40%BW, 1.1±1.4mm at 30%BW, and 0.9±1.2mm at 20%BW in the stable THA group. There were statistically significant differences in the separation distance between the groups in all ranges of traction force. The femoral offset difference between the operated side and the healthy side was −1.2±5.6mm in the unstable THA group and 3.1±4.8mm in the stable THA group. There were no significant difference in the femoral offset difference, however the femoral offset tends to be small in the unstable THA group compared to the stable THA group (P=0.05). The leg length discrepancy was −3.1±11.6mm in the unstable THA group and 2.7±7.1mm in the stable THA group. There were no significant difference in the leg length discrepancy (P=0.12). Conclusion. The separation distance of the head and the cup during leg distal traction in the unstable THA group is about four times larger than that in the stable THA group. The femoral offset tended to be smaller in the unstable THA group compared to the stable THA group

Fifteen-year survivorship studies demonstrate that total knee replacement have excellent survivorship, with reports of 85 to 97%. However, excellent survivorship does not equate to excellent patient reported outcomes. Noble et al. reported that 14% of their patients were dissatisfied with their outcome with more than half expressing problems with routine activities of daily living. There is also a difference in the patient's subjective assessment of outcome and the surgeon's objective assessment. Dickstein et al. reported that a third of total knee patients were dissatisfied, even though the surgeons felt that their results were excellent. Most of the patients who report lower outcome scores due so because their expectations are not being fulfilled by the total knee replacement surgery. Perhaps this dissatisfaction is a result of subtle soft tissue imbalance that we have difficulty in assessing intraoperatively and postoperatively. Soft tissue balancing techniques still rely on subjective feel for appropriate ligamentous tension by the surgeon. Surgical experience and case volume play a major role in each surgeon's relative skill in balancing the knee properly. New technology of “smart trials” with embedded microelectronics and accelerometers, used in the knee with the medial retinaculum closed, can provide dynamic, intra-operative feedback regarding knee quantitative compartment pressures and component tracking. After all bone cuts are made using the surgeon's preferred techniques, trial components with the sensored tibial trial are inserted and the knee is taken through a passive range of motion. After visualizing the resultant compartment pressures and tracking data on a graphical interface, the surgeon can decide whether to perform a soft tissue balance or a minor bone recuts. If soft tissue balancing is chosen, pressure data can indicate where to perform the release and allow the surgeon to assess the pressure changes as titrated soft tissue releases are performed. A multi-center study using smart trials has demonstrated dramatically better outcomes out to three years

Introduction. The knee is the most commonly injured joint in sporting accidents, leading to substantial disability, time off work and morbidity (1). Treatment and assessment vary around the UK (2), whilst there remains a limited number of high-quality randomised controlled trials assessing first time, acute soft tissue knee injuries (3,4). As the clinical and financial burden rises (5), vital answers are required to improve prevention, diagnosis, treatment, rehabilitation, and delivery of care. In association with the James Lind Alliance, this BASK, BOSTAA and BOA supported prioritising exercise was undertaken over a year. Methods. The James Lind Alliance methodology was followed; a modified nominal group technique was used in the final workshop. An initial survey invited patients and healthcare professionals to submit their uncertainties regarding soft tissue knee injury prevention, diagnosis, treatment, rehabilitation, and delivery of care. Seventy-four questions were formulated to encompass common concerns. These were checked against best available evidence. Following the interim survey, 27 questions were taken forward to the final workshop in January 2023, where they were discussed, ranked, and scored in multiple rounds of prioritisation by groups of healthcare professionals, patients, and carers. Results. Over 1000 questions were submitted initially. Twenty-seven were taken forward to the final workshop following the surveys. Nearly half of the responses were from patients/carers. The Top 10 (Figure 1) includes prevention, diagnosis, treatment, and rehabilitation questions, reflecting the concerns of patients, carers, and a wider multidisciplinary team. Conclusion. This validated process has generated an important, wide- ranging Top 10 priorities for future soft tissue knee injury research. These have been submitted to the National Institute for Health and Care Research and are now available for researchers to investigate. The final 27 questions which were taken to the final workshop have also been published on the James Lind Alliance website. Research into these questions will lead to future high-quality research, thus improving patient care & outcomes. For any figures or tables, please contact authors directly

Optimal soft tissue tension maximises function following total knee arthroplasty. Excessive tension may lead to stiffness and or pain, while inadequate tension can lead to instability. Composite component thickness is a prime determinant of this soft tissue tension. The variable component thickness provided by polyethylene inserts generally allows for 2–3mm incremental change. This study analyzed the effect of 1-mm incremental changes in polyethylene thickness on soft tissue tension. Our hypothesis was that soft tissue tension would be markedly affected by increases in insert thickness. Computer assisted TKA was performed on eight cadaveric knee specimens (four pairs). The knees were passively moved through full flexion-extension range of motion, for each tibial construct thickness. Kinematics were recorded using the computer navigation software. Soft tissue tension was analyzed by measuring compartmental loads. A validated load cell instrumented tibial insert was used to measure medial and lateral compartmental loads independently. The effect of 1-mm increments in polyethylene thickness on compartmental loads was evaluated. An increase in compartmental loads was measured with increasing insert thickness. Loading in contralateral compartments showed differing behaviour, reflecting varying tension in the medial and lateral sides. Many generated loads showed a reduction after reaching a maximal level with further increase in insert thickness (seven of eight specimens), indicative of tissue failure, although there were no overt indications of failure during the procedure. With a 1-mm increase in insert thickness, six of eight specimens showed an increase in peak loads greater than 100N at some point in the testing procedure, although not always with the same shim thickness. Compartmental loads varied as a function of insert thickness. Most specimens showed signs of soft tissue “micro-failure”. The high sensitivity of compartmental loads to a 1-mm incremental increase is significant and has not been previously appreciated, especially intra-operatively. Currently available inserts with 2–3mm incremental sizes may make obtaining optimal soft tissue tension difficult. In addition to the current focus of obtaining accurate leg alignment, further computer-assisted techniques are required to address soft tissue tension

The anatomy of the prevertebral region of the neck is of vital importance to orthopaedic surgeons when managing cervical spine trauma. Lateral radiographs are used in the acute assessment of this area as they are readily available and cost effectiveness. Thickening of the retropharyngeal space on a radiograph may be highly suggestive of serious and life-threatening pathologies. Accurate interpretation of radiological evidence is essential to assist the clinician in diagnosis. Current guidelines for radiological measurement state that these prevertebral soft tissues should not exceed 5mm at the midvertebral level of C3 and 20mm at C7. A ratio between soft tissue measurements and the width of the corresponding vertebra has also been championed as this takes into account magnification errors and variation in patient body habitus. Soft tissue measurements greater than 30% of the upper cervical vertebral bodies and greater than 100% of the lower cervical vertebral bodies are considered to be abnormal. The aim of this study was to assess reliability of current radiological guidelines on soft tissue measurement. A review of 200 consecutive normal lateral soft tissue cervical spine radiographs was undertaken. Patients were included if they were immobilised for blunt trauma and were aged 18 or older. Each patient included had cervical pathology excluded by a combination of clinical examination, flexion-extension views, CT and or MRI. Exclusion criteria included those patients with pre-existing cervical or retropharyngeal pathology, those who had been intubated or had a nasogastric tube passed. Two reviewers independently assessed soft tissue and bony widths at C3 and C7 using the PACs Software. All measurements were taken at the mid vertebral level, not at the end plates to ensure any anterior osteophytes did not create a falsely wide measurement. Plane film radiographs of 107 males and 93 females were included with an average age of 53. At the C3 level, mean soft tissue widths were 4.7mm ± 0.84mm SD and ranged from 2.7 to 7.4mm. The mean soft tissue width at C7 was 14.4mm ± 2.8mm SD with a range of 7.1 to 21.0 mm. Our results show 21.5% (43/200) of the patients exceeded the 5mm upper limit and 20% (40/200) exceeded the soft tissue to vertebra ratio at C3. Only 1% (2/200) of patients exceeded the upper limit of 20mm at C7 and only 2% (4/200) exceeded the soft tissue to vertebra ratio. The C3 guideline for maximum soft tissue widths has a poor specificity (78.5%) and the soft tissue to vertebral ratio at this level may also lead to further unnecessary investigation, as it too has a specificity of only 80%. However, the guidelines for PVST measurements at C7 are much more reliable with a specificity of 99.5% for the absolute measurement and 99% for the soft tissue to vertebra ratio. The ratio measurement has not conferred any significant diagnostic benefit over the static measurement. Current guidelines overestimate injuries at the C3 level but seem appropriate at the C7 level. There is no major benefit to using a ratio measurement over an absolute value

Aim: To describe the radiographic findings of soft tissue sarcoma. Materials and Method: The retrospective review of 100 consecutive patients with a histological diagnosis of primary soft tissues sarcoma of the extremities. Results: Fifty five patients had plain radiographs at initial presentation. This was mainly due to the fact that most patients were tertiary referrals or had other initial imaging. Histological diagnosis in these patients was: liposarcoma in 24 patients, leiomyosarcoma in 8, undifferentiated spindle cell sarcoma in 5, malignant schwannoma in 4, synovial sarcoma in 4, MFH in 2, fibrosarcoma in 2, haemangiopericytoma, epithelioid sarcoma, malignant GCT, melanoma and spindle cell histiocytoma in one. The upper limb was involved in 18 patients and the lower limb was involved in 37. Thirty-five (63.6%) patients had a visible soft tissue mass on plain film. Eleven had mineralisation within the soft tissue mass and seven had either bone involvement or periosteal response. Those with a distinct soft tissue mass and evidence of fat content on plain film were noted to be diagnosis of liposarcoma in 86.7% of the cases. Mineralization was noted in synovial sarcoma (2), liposarcoma (3), leiomyosarcoma (1), MFH (2) and poorly differentiated sarcomas (2). Conclusion: The plain radiograph is useful in assessing soft tissue tumour and abnormality is seen in 2/3 of cases reviewed. Mineralization as a radiographic finding features in malignant sarcoma notably liposarcoma. With tumours demonstrating fat on plain film this can correlate with MRI and facilitate surgical treatment avoiding biopsy

Most orthopaedic surgeons believe that total knee replacement has superb patient outcomes. Long-term results are excellent, with one study showing 15 year survivorship of 97%. However, our objective assessments of our patients' results are greater than patients' subjective assessments. In a study by Dickstein of total knee patients, one-third were not satisfied even though they were all thought to have had successful results by their orthopaedic surgeons. Noble and Conditt's study showed 14% of patients dissatisfied with their outcome with more than half expressing problems with routine activities of daily living. We are puzzled by this patient dissatisfaction since radiographs usually show normal component alignment and positioning. Perhaps some of these patients have subtle soft tissue imbalance and kinematic maltracking. Excellent aligned bone cuts can be expected with modern instrumentation, especially if patient specific cutting instruments or computer navigation are used. However, inadequate instrumentation exists for soft tissue balancing. It is usually based on feel and visual estimation. Soft tissue balancing techniques are difficult to teach and perform by a less experienced surgeon. Smart trials with load bearing and alignment sensors, which can be used with the medial retinaculum closed, will demonstrate the total knee kinematics and quantify soft tissue balance. Graduated soft tissue balancing can be performed while visualising changes in compartment loads. Studies are ongoing with smart trials to establish evidence-based clinical algorithms for soft tissue balancing and document the effects of these techniques on patient satisfaction and long-term outcome

In a study by Dickstein, one-third of total knee patients were not satisfied even though they were all thought to have had successful results by their orthopaedic surgeons. Noble and Conditt's study showed 14% of patients dissatisfied with their outcome with more than half expressing problems with routine activities of daily living. This occurs despite improvements in instrumentation to obtain proper alignment and implants with excellent kinematics and wear characteristics. Perhaps this dissatisfaction is a result of subtle soft tissue imbalance. Soft tissue imbalance can result in almost a third of early TKR revisions. Soft tissue balancing techniques still rely on subjective feel for appropriate ligamentous tension by the surgeon. Surgical experience and case volume play a major role in each surgeon's relative skill in balancing the knee properly. New technology of “smart trials” with embedded microelectronics, used in the knee with the medial retinaculum closed, can provide dynamic, intraoperative feedback regarding quantitative compartment pressures and component tracking. While visualising a graphical interface, the surgeon can assess the effect of sequential soft tissue releases performed to balance the knee. These smart trials also have imbedded accelerometers used to confirm that one is balancing a properly aligned knee and to provide the option of doing small bony corrections rather than soft tissue releases to obtain balance. A multi-center study using smart trials is demonstrating dramatically better outcomes at six months

Purpose: To determine the mode of presentation of soft tissue sarcomas to a tertiary centre and the factors associated with a delay in diagnosis and referral. Methods and Results Between 2000 and 2002, we identified 120 patients with primary soft tissue sarcomas histologically verified at our institution. We reviewed the case histories, referral letters and the histology reports in all cases. The mean age of the study group was 54.5 (range 10 to 91 years). Pathological diagnoses included 32 liposarcomas, 20 malignant fibrous histiocytomas, 19 synovial sarcomas, 12 leiomyosarcomas, 9 fibrosarcomas, 7 spindle cell sarcomas, 4 pleomorphic sarcomas, 3 identified only as high grade soft tissue sarcomas, 3 epithelioid sarcomas, 2 extraosseous Ewing’s sarcomas, 2 malignant round cell tumours and one each of neurofibroma, malignant peripheral nerve sheath tumour, angiosarcoma, alveolar cell sarcoma, extraosseous chondrosarcoma, extraosseous osteosarcoma and clear cell sarcoma of tendon sheath. Presenting features included a discrete lump or diffuse swelling in 115 patients (95.8%). Pain was not a feature in 69 patients. 3 patients (2.5%) presented with pain alone and 2 patients (1.7%) with varicosities. 116 patients (96.7%) were referred to our unit as a possible soft tissue sarcoma. 4 patients were referred as suspected benign lesions requiring specialist assessment owing to size and location. 46 patients (38.3%) ignored their swelling, resulting in a delay to presentation to their local units. In only 13 patients was pain a feature. These were not considered to be true delayed referrals. 24 patients (20%) experienced a delayed referral to our unit. An alternative diagnosis was suggested in 7 patients by preliminary imaging investigations. A ‘Whoops procedure’ was performed in 14 patients. 3 patients were initially misdiagnosed as muscular injuries, with consequent conservative management resulting in delay. Conclusion: Soft tissue sarcomas are relatively rare when considered alongside benign soft-tissue lesions. Pain is an infrequent feature, which may result in patients undervaluing their significance and delay their initial presentation to a doctor. Delayed referral is relatively common, although may not always be avoidable. Clinicians should maintain a high level of suspicion when dealing with soft-tissue lesions, with referral to a specialist centre whenever concern exists as to the nature of the lesion

Aim: To identify the clinical features of patients who present with soft tissue metastases (from a cancer elsewhere) and to identify the source of the cancer. Method: In a database containing details of 7242 patients referred to our unit for investigation of a soft tissue lump, only 100 of these patients were found to have a soft tissue metastasis (1.4%). We analysed their presenting features and identified the site of the primary malignancy. Results: The most common presentation of soft tissue metastases was a painless lump The lumps ranging from 2 to 35 cm (mean 8.3cm) with 78% of the lumps located deep to the fascia. The mean age at presentation was 62 and there were equal males and females. 53 had a past history of malignancy. Of these 53, 52 had metastases from the same primary (lung 11, melanoma 10, kidney 9, GI tract 4, breast 6, bladder 4 and others in 9). The other 47 patients had no past history of malignancy and the metastasis was the first presentation of malignancy. The primary sites in these cases were: lung in 19, GI tract 4, kidney 2, melanoma 9, other 3 and unknown (despite investigations) in 10. There was no correlation of the site of the metastases with the primary tumour. Of the 7242 patients with soft tissue lumps, 476 had a past history of malignancy. Of these patients, only 12% actually had a soft tissue metastasis while 28% had a benign diagnosis, 55% a soft tissue sarcoma and 5% other malignancy. Conclusion: Patients with a past medical history of malignancy and a new soft tissue lump have a 12% chance of it being a soft tissue metastasis. If a lump proves to be a soft tissue metasasis, the lung is the most common primary site

Lymph node metastasis in soft tissue sarcoma is considered to be a rare event (1.6–8.2%), From 1986 to 2001 1066 patients with extremity soft tissue sarcoma were treated surgically (+/− adjuvant therapy) at our institution. Thirty-nine patients (3.6%) were identified with lymph node metastasis, most common histological subtypes were: Epitheliod sarcoma (3/15), rhabdomyosarcoma (4/21), clear cell sarcoma (2/18), and angiosarcoma (2/18). Comparing expected five- year survivorship, we found that surprisingly in this study, extremity soft tissue sarcoma patients initially presenting with lymph node metastases had survival comparable to patients with high grade soft tissue sarcoma and no metastases. To determine the outcome in patients with soft tissue sarcoma (STS) of the limbs that presented with lymph node metastasis (LNM) at diagnosis or developed them after it, comparing to all STS of limbs population that was treated at our center. LNM in soft tissue sarcoma is considered to be a rare event (1.6–8.2%) with a devastating effect on the outcome,our study represent one of the largest reported cohorts, and suggest that agressive approach to LNM might contribute to survivorship. Thirty-nine patients (3.6%) were identified with LNM along their course of disease. Thirteen patients presented with both lymphatic and systemic disease while twenty-six had isolated LNM at time of diagnosis. The mean follow-up from diagnosis of the primary tumor was 46.3 months (range zero to one hundred and forty-eight), and from diagnosis of lymph node involvement was 29.9 months (range zero to one hundred and twenty). Expected five year survival in patients initially presenting with LNM was comparable to patients with high grade soft tissue sarcoma and no metastases. From Jan’ 1986 to Dec’ 2001 1066 patients with extremity STS were treated at our institution. Fifteen patients presented with LNM at time of first diagnosis, and twenty-four subsequently developed LNM after it. Linear regression analysis and Kaplan-meier curves were used to compare expected survivorship in all patients with STS of limbs. Comparing expected five- year survivorship, we found that Surprisingly in this study, extremity STS patients initially presenting with LNM had survival comparable to patients with high grade soft tissue sarcoma and no metastases

Objective. Although both accurate component placement and adequate soft tissue balance have been recognized as essential surgical principle in total knee arthroplasty (TKA), the influence of intra-operative soft tissue balance on the post-operative clinical results has not been well investigated. In the present study, newly developed TKA tensor was used to evaluate soft tissue balance quantitatively. We analyzed the influence of soft tissue balance on the post-operative knee extension after posterior-stabilized (PS) TKA. Materials and Methods. Fifty varus type osteoarthritic knees implanted with PS-TKAs were subjected to this study. All TKAs were performed using measured resection technique with anterior reference method. The thickness of resected bone fragments was measured. Following each bony resection and soft tissue releases, we measured soft tissue balance at extension and flexion of the knee using a newly developed offset type tensor. This tensor device enabled quantitative soft tissue balance measurement with femoral trial component in place and patello-femoral (PF) joint repaired (component gap evaluation) in addition to the conventional measurement between osteotomized surfaces (osteotomy gap evaluation). Soft tissue balance was evaluated by the center gap (mm) and ligament balance (°; positive in varus) applying joint distraction forces at 40 lbs (178 N). Active knee extension in spine position was measured by lateral X-ray at 4 weeks post-operatively. The effect of each parameter (soft tissue balance evaluations, thickness of polyethylene insert and resected bone) on the post-operative knee extension was evaluated using simple linear regression analysis. P<0.05 was considered statistically significant. Results. The thickness of resected bone, flexion center gap and ligament balance at extension and flexion had no correlations to the knee extension angle. Thickness of polyethylene insert correlated positively to knee extension (r=0.38, p=0.007). Significant positive correlation were found between extension center gap in both osteotomy and component gap evaluation to the post-operative knee extension. The coefficient of correlations were 0.33 (p=.02) with osteotomy gap and 0.47 (p=0.0007) with component gap evaluation. Discussion and Conclusion. In the present study, extension center gap was found to positively correlate to the early post-operative knee extension. The extension center gap could be considered as the summation of the simultaneous gap from bone resections and the elongation of soft tissue envelope under joint distraction force applied by tensor. The soft tissue with the lower stiffness would be elongated more, and result in the larger center gap. Accordingly, the stiffness of the soft tissue envelope might play an important role on the magnitude of extension center gap and the post-operative knee extension. Furthermore, the center gap in component gap evaluation had higher coefficient of correlation comparing to that in osteotomy gap. Proposed component gap evaluation in soft tissue balance measurement might be more physiological and relevant to the joint condition after TKA, and useful to predict post-operative clinical results

Background. The National Institute of Clinical Excellence (NICE) published clinical guidelines in 2006 defining urgent referral criteria for soft tissue sarcoma to help improve the diagnostic accuracy and overall outcome. Despite these guidelines inadvertent excisions of soft tissue sarcomas continue to occur with alarming frequency potentially compromising patient outcomes. Objective. We reviewed the East Midlands Sarcoma Service experience of treating inadvertent excision of STSs and highlight the patient profile, referral pattern, subsequent management and oncological outcome associated with inadvertent resection. Methods. Patients were identified from our sarcoma database and a retrospective case note review performed. Results. Over a period of 32 months, 42 patients presented to our specialist centre after unplanned excision of soft tissue sarcomas. There were 29 men and 13 women, with a mean age at presentation of 59 years (19-90). 50% of the tumours were located in lower extremity, 33% around the trunk and 17% in the upper extremity. The unplanned surgery was most commonly from general surgeons, non-specialist orthopaedic surgeons, general practitioners followed by plastic surgeons. Re-resection was undertaken in 40 (95.2%) cases to achieve clear margins. Residual tumour was present in 74% of cases. Resected specimen histology was high grade in 90% of cases. Limb salvage surgery was not possible in 4 cases. Conclusion. Unplanned excision of sarcoma by non-oncologic surgeons remains a problem. It appears that it is equally prevalent in varied surgical community and general practitioners. Patients with soft tissue masses of unknown identity should be appropriately imaged and if the diagnosis remains unclear be transferred to centres that specialize in treating sarcomas for biopsy and adequate initial resection. Implementation of NICE guidelines and local strategies could improve the expedient management of these patients

Pseudo-patella baja (PPB) describes narrowing of the distance between the patella and the tibia without shortening of the PT and occurs following Total Knee Arthroplasty (TKA), where the tibial prosthesis plus insert are thicker than the resected tibia. Soft tissue balancing is an important factor in the success of TKA, but if extensive may necessitate the use of thicker tibial inserts with the risk of creating a PPB. Patients who undergo extensive soft tissue releases during TKA, with resultant use of thicker tibial inserts will develop a PPB, with increased risk of patella pathology. 506 patients aged 40-90 years underwent 526 Kinemax TKAs, performed by 7 surgeons in 5 centres between 1999 and 2002. The extent of soft tissue releases and the thickness of tibial inserts were recorded. Pre- and post-operative lateral radiographs were measured by an independent observer, using the Caton-Deshamps method to assess patella position. The patients were assessed using the Oxford Knee Score and the American Knee Society Clinical Rating System, with a minimum follow-up of 12 months. 1. TKA surgery creates a Pseudo-Patella Baja. Excluding patients with a pre-operative patella baja, PPB was introduced into 26.7% of patients. (p=0.000). 2. The incidence of pseudo-patella baja increased with the extent of soft tissue release; Minimal, Moderate or Extensive. (p=0.000). 3. The incidence of pseudo-patella-baja increased with increases in insert thickness. Three groups were identified: Inserts 8 mm, inserts 10-12mm, and inserts 15-22 mm. (p=0.035). There was no correlation between the incidence of PPB and changes in clinical or functional outcome, as measured using the OKS and AKSS. Pseudo-patella baja occurs in 26% of all patients following TKA, and in 46% of patients in whom extensive soft tissue releases have been performed and/or large tibial inserts have been used. At 12 months, no detrimental outcomes were attributable to the incidence of pseudo-patella baja

Introduction: Distraction osteogenesis has been used as a method of generating new bone in limb lengthening and deformity realignment; and is achieved in our unit though the use of the Sheffield Ring Fixator. The development of soft tissue tension creates an entirely different mechanical environment, and can often result in severe complications during treatment. Fixators must therefore be able to resist these forces. Furthermore, biomechanical modelling is very different from fracture and bone gap simulation. The model developed in this study intended to look at linear distraction, i.e. lengthening. Aims: To create a mechanical model that simulates the soft tissue effects during lengthening with an external fixator. To obtain a synthetic material with similar passive tensile properties to that measured in lengthened soft tissue. To measure the effect of tensioned synthetic soft tissue on osteotomy motion and multi-planar stiffness during cyclic loading. Materials and Methods: A standard two 150mm ring frame was mounted on an acrylic rod, with a centrally placed osteotomy gap of 75mm. One ring was fixed with wires and the other with screws. An inter-fragmentary motion device was attached across the osteotomy, to measure axial, angular and shear deformation with both axial and off-axis loading. Soft tissue tension was simulated with the use of neoprene rubber sheeting, attached to the nylon rod by Jubilee clips, with a gap anteriorly or medially. Extensive tensile testing was performed to determine the visco-elastic behaviour of the rubber, which showed it to be consistent and reliable. Tension of a similar magnitude to lengthened muscle (35–125N) was achieved, and could be accurately predicted for certain distraction lengths. The stiffness of the frame was calculated from osteotomy motion with various distraction lengths both with the rubber attached and without. Results: Tension in the soft tissues summates with the force applied in loading, with the effect of increasing the axial stiffness of the fixator by up to 70N, with a directly proportional relationship. It also acts as a restraint for shear and angulatory motion. In anterior and lateral loading positions however, the angulation stiffness remains low; this is thought to be due to the unequal distribution of soft tissues around the bony column, as seen in vivo. The stiffness of the frame is lowered by increasing the distance between rings; this effect can be counteracted by soft tissue tension in axial stiffness, but less so for angular and shear. Conclusions: We conclude that osteotomy stability is dependent on soft tissue tension, and the magnitude of tension greatly alters the stiffness characteristics of the external fixator. This study highlights the important role of soft tissue tension in biomechanical modelling and clinical limb lengthening, and has exciting ramifications for future orthopaedic models

Introduction. Accurate soft tissue balancing has been recognized as important as alignment of bony cut in total knee arthroplasty (TKA). In addition, using a tensor for TKA that is designed to facilitate soft tissue balance measurements throughout the range of motion with a reduced patello-femoral (PF) joint and femoral component in place, PF joint condition (everted or reduced) has been proved to have a significant effect for intra-operative soft tissue balance. On the other hand, effect of patellar height on intra-operative soft tissue balance has not been well addressed. Therefore, in the present study, we investigated the effect of patellar height by comparing intra-operative soft tissue balance of patella higher subjects (Insall-Salvati index>1) and patella lower subjects (Insall-Salvati indexâ‰/1). Materials and methods. The subjects were 30 consecutive patients (2 men, 28 women), who underwent primary PS TKA (NexGen LPS-flex PS: Zimmer, Warsaw, IN, USA) between May 2003 and December 2006. All cases were osteoarthritis with varus deformity. Preoperative Insall-Salvati index (ISI) was measured and patients were divided into two groups; the patella higher group (ISIï1/4ž1: 18 knees average ISI was 1.12) and the patella lower group (ISIâ‰/1; 12 knees average ISI was 0.94). Component gap and ligament balance (varus angle) were measured using offset-type tensor with 40lb distraction force after osteotomy with the PF joint reduced and femoral trial in place at 0, 10, 45, 90, 135 degrees of knee flexion. Data of two groups were compared using unpaired t test. Results. Component gap was increased from 0 to 90 degrees of knee flexion and decreased at 135 degrees of knee flexion in both groups. Component gaps of the patella higher group in average were 10.9, 14.3, 16.6, 18.2, 16.8 mm at 0, 10, 45, 90, 135 degrees of knee flexion, respectively. Component gaps of the patella lower group in average were 9.6, 13.6, 14.6, 15.5, 14.0 mm at 0, 10, 45, 90, 135 degrees of knee flexion, respectively. When comparing two groups, component gaps of the patella higher group showed larger trend than those of the patella lower group. Especially at 90 and 135 degrees of knee flexion, the patella higher group showed significant larger values than the patella lower group (p<0.05). Varus angles of the patella higher group in average were 2.2ï1/4Œ3.4ï1/4Œ5.0ï1/4Œ5.9ï1/4Œ6.1 degrees at 0, 10, 45, 90, 135 degrees of knee flexion, respectively. Varus angles of the patella lower group in average were 1.7ï1/4Œ2.8ï1/4Œ4.4ï1/4Œ4.9ï1/4Œ4.6 degrees at 0, 10, 45, 90, 135 degrees of knee flexion, respectively. Varus angles of the patella higher group showed slight larger trend than those of the patella lower group, however there was no significant differences between two groups. Discussion. In the present study, the patella higher group showed significant larger component gaps than the patella lower group at high flexion angles (90, 135 degree). This result suggests that smaller pressure on extensor mechanism of the patella higher group has led to larger component gaps at higher flexions. In conclusion, pre-operative measurement of ISI can help surgeons predict intra-operative soft tissue balance

Introduction. Balancing of joint gap is a prerequisite in total knee arthroplasty (TKA). Recently, the tensor has been developed which can measure the joint gap with the patellofemoral joint reduced for more physiological assessment, and the results for osteoarthritis (OA) patients indicated that the flexion gap is larger than the extension gap during posterior-stabilized (PS) TKA. However with respect to the rheumatoid arthritis (RA) patients, the soft tissue balance in TKA is still unknown. Therefore, the purpose of this study was toinvestigate thecharacteristics of thejoint gap during TKAsurgeryforpatients with RA. Methods. We implanted 90 consecutive knees with a PS TKA using a NexGen LPS-flex (Zimmer, Warsaw, IN). OA was the underlying disease in 60 knees and RA was the disease in30 knees. Surgical procedure. We performed all operations with a measured resection technique. The rotational position of the femoral component was determined based on the epicondylar axis of the femur with anterior reference for anteroposterior sizing. Joint gap measurements. After bone cuts and soft tissue balancing, we measured the joint gap with the femoral component in position using seesaw-type tenser device with the patella reduced position after repair of the medial arthrotomy with a few stitches. The center width and asymmetry (tilting) of joint gaps under 40-lb distracting force were measured at 0 degree extension and 90 degrees of knee flexion. Results. The changes in the joint gap from 0 to 90 degrees were 3.2 ± 0.3 mm in OA group and 4.3 ± 0.4 mm in RA group. The increase of joint gap from 0 to 90 degrees in RA was significantly larger than that in OA group (Figure 1). The tilting angle of the joint gap (varus gap expressed as positive values) at 90 degrees of knee flexion in RA group (5.3 ± 0.5 degrees) was significantly larger than that in OA group (2.6 ± 0.4 degrees) (Figure 2). In RA group, there was a positive correlation (r= 0.34, p <0.05) between the increase of joint gap from 0 to 90 degrees and the tilting angle of the joint gap at 90 degrees of knee flexion (Figure 3). Discussion. In this study, the increase of joint gap from 0 to 90 degrees in RA group was significantly larger than that in OA group. In addition, the lateral gap in knee flexion, calculated from the tilting angle of the joint gap, was significantly larger in RA group and was correlated with the increase of joint gap from 0 to 90 degrees of knee flexion. These differences could be attributed to reduced stiffness of the lateral structure, such as lateral collateral ligament and popliteofibular ligament, as well as the extensor mechanism in patients with RA. Therefore, it is necessary to considerthe individual stiffness of soft tissues, together with the applied tension, to decide the rotation of femoral component by reference to the flexion gap during TKA for RA patients