Brachial plexus tumours (BPT) and peripheral nerve sheath tumours (PNST) are largely benign in nature, with malignant tumours being rare and presenting significant surgical challenges. Excision of benign tumours may relieve pain and other symptomology. This retrospective study analysed data from 138 PNST and 92 BPT patients managed by a single consultant orthopaedic or plastic surgeon experienced in nerve tumour surgery between January 1999 to December 2019. The most common benign tumours were schwannomas and neurofibromas, with sarcomas being the most common malignant tumour.

In the PNST group 30 patients were managed by observation only. Twenty patients underwent trucut biopsy, 21 patients underwent biopsy and surgical excision and 56 patients underwent surgical excision only. There were nine complications, with two significant neurological deficits requiring further surgical intervention. No recurrence of tumours occurred in this group.

In the BPT group 16 patients were managed by observation only. Seven patients underwent trucut biopsy, 16 patients biopsy and surgical excision and 44 BPT patients underwent surgical excision only. Sixteen patients had complications with two significant complications requiring urgent further surgical intervention. Seven patients had recurrence of tumours which presented as metastases, with three patients requiring further surgery to remove recurrence of tumours.

BPT patients are more complex and present with both benign and malignant lesions and are therefore more prone to complications due to the complex nature of the surgery and higher recurrence rate of tumours than PNST. Benign tumours in both groups can be safely managed conservatively if patients’ symptomology is acceptable.

The knee joint displays a wide spectrum of laxity, from inherently tight to excessively lax even within the normal, uninjured population. The assessment of AP knee laxity in the clinical setting is performed by manual passive tests such as the Lachman test. Non-invasive assessment based on image free navigation has been clinically validated and used to quantify mechanical alignment and coronal knee laxity in early flexion. When used on cadavers the system demonstrated good AP laxity results with flexion up to 40°. This study aimed to validate the repeatability of the assessment of antero-posterior (AP) knee joint laxity using a non-invasive image free navigation system in normal, healthy subjects.

Twenty-five healthy volunteers were recruited and examined in a single centre. AP translation was measured using a non-invasive navigation system (PhysioPilot) consisting of an infrared camera, externally mounted optical trackers and computer software. Each of the volunteers had both legs examined by a single examiner twice (two registrations). The Lachman test was performed through flexion in increments of 15°. Coefficients of Repeatability (CR) and Interclass Correlation Coefficients (ICC) were used to validate AP translation. The acceptable limits of agreement for this project were set at 3mm for antero-posterior tibial translation.

The most reliable and repeatable AP translation assessments were at 30° and 45°, demonstrating good reliability (ICC 0.82, 0.82) and good repeatability (CR 2.5, 2.9). The AP translation assessment at 0°, 15°, 75° and 90° demonstrated moderate reliability (ICC ≤ 0.75), and poor repeatability (CR ≥3.0mm).

The non-invasive system was able to reliably and consistently measure AP knee translation between 30° and 45° flexion, the clinically relevant range for this assessment. This system could therefore be used to quantify abnormal knee laxity and improve the assessment of knee instability and ligamentous injuries in a clinic setting.