Alteration of Ligamento-Muscular Reflex Patterns After Cutaneous and Periarticular Desensitization of the Basal Thumb Joint: An Electromyographic Study.

PURPOSE: Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1 stabilizing muscles in healthy volunteers. However, it remains unclear how this ligamento-muscular reflex pattern is altered after anesthetizing sensory skin receptors and administering a further periarticular block around the CMC-1 joint, which may influence the dynamic aspects of joint stability. METHODS: Ligamento-muscular reflexes were obtained from the extensor pollicis longus, abductor pollicis longus, abductor pollicis brevis, and the first dorsal interosseous muscles in 10 healthy participants after establishing superficial anesthesia of the skin around the CMC-1. The DRL was stimulated with a fine wire electrode while EMG activities were recorded during isometric tip, key, and palmar pinch. The measurements were repeated after an additional periarticular CMC-1 block using 5 ml of 1% lidocaine. Average EMG values were analyzed to compare the prestimulus and poststimulus activity. RESULTS: Statistically significant changes in poststimulus EMG activity were observed in all 4 muscles and all 3 tested thumb positions. A markedly reduced activity in all 4 muscles was observed in the palmar position, followed by the tip and key pinch positions. Almost no reactions were observed in the first 20 ms poststimulus for all muscles in all positions. CONCLUSIONS: Superficial skin anesthesia and an additional periarticular CMC-1 block anesthesia resulted in a reduced ligamento-muscular reflex pattern in all 4 muscles. CLINICAL RELEVANCE: Ligamento-muscular reflexes play an important role in dynamic CMC-1 joint stability. The elimination of early reactions, those considered joint-protective reflexes, is a potential risk factor for developing osteoarthritis or injury because it results in an inability to adequately protect and stabilize the joint in sudden movements.

Ligamento-Muscular Reflex Patterns Following Stimulation of a Thumb Carpometacarpal Ligament: An Electromyographic Study.

PURPOSE: The dorsoradial ligament (DRL) is essential for stability of the first carpometacarpal joint (CMC1) and is innervated with nerve endings and mechanoreceptors known to contribute to joint proprioception. The influence of these nerve endings on the neuromuscular stability of CMC1 is not yet known. This study investigated whether a ligamento-muscular reflex pathway is present between the DRL and CMC1 muscles. METHODS: Ten healthy subjects (5 women and 5 men, mean age 28 years; range, 24-37 years) were included. Four primary CMC1 stabilizing muscles were investigated: the extensor pollicis longus, abductor pollicis longus (APL), abductor pollicis brevis, and first dorsal interosseous. Needle electrodes were inserted into each muscle and a fine-wire electrode was inserted into the DRL. The DRL was stimulated at 200 MHz while EMG activities in the muscles were recorded during isometric tip, key, and palmar pinch. Average EMG values were analyzed to compare prestimulus (t1) with post-stimulus (t2) activity. RESULTS: Poststimulus changes were observed in all 4 muscles and 3 positions tested. During tip pinch we observed mass inhibition with a decrease in all muscle amplitudes. In key pinch we observed a rapid co-contraction response. Rapid inhibitory response of antagonistic musculature was observed during palmar pinch. The APL was the only muscle to react within 20 ms after stimulation. CONCLUSIONS: We identified CMC1 ligamento-muscular reflexes. The mass inhibition of activity observed during tip pinch indicated a protective ligamento-muscular relation that affects all 4 muscles. The co-contractions observed promote joint stability. The fast response in the APL, coupled with its neuroanatomical proximity to the DRL, indicate a particular role in CMC1 proprioception. CLINICAL RELEVANCE: Proper ligamentous support and retained innervation is likely important for adequate joint function; their innate functions ought to be considered when planning surgical or orthotic treatments.

Ultrastructure and innervation of thumb carpometacarpal ligaments in surgical patients with osteoarthritis.

BACKGROUND: The complex configuration of the thumb carpometacarpal (CMC-1) joint relies on musculotendinous and ligamentous support for precise circumduction. Ligament innervation contributes to joint stability and proprioception. Evidence suggests abnormal ligament innervation is associated with osteoarthritis (OA) in large joints; however, little is known about CMC-1 ligament innervation characteristics in patients with OA. We studied the dorsal radial ligament (DRL) and the anterior oblique ligament (AOL), ligaments with a reported divergent presence of mechanoreceptors in nonosteoarthritic joints. QUESTIONS/PURPOSES: This study's purposes were (1) to examine the ultrastructural architecture of CMC-1 ligaments in surgical patients with OA; (2) to describe innervation, specifically looking at mechanoreceptors, of these ligaments using immunohistochemical techniques and compare the AOL and DRL in terms of innervation; and (3) to determine whether there is a correlation between age and mechanoreceptor density. METHODS: The AOL and DRL were harvested from 11 patients with OA during trapeziectomy (10 women, one man; mean age, 67 years). The 22 ligaments were sectioned in paraffin and analyzed using immunoflourescent triple staining microscopy. RESULTS: In contrast to the organized collagen bundles of the DRL, the AOL appeared to be composed of disorganized connective tissue with few collagen fibers and little innervation. Mechanoreceptors were identified in CMC-1 ligaments of all patients with OA. The DRL was significantly more innervated than the AOL. There was no significant correlation between innervation of the DRL and AOL and patient age. CONCLUSIONS: The dense collagen structure and rich innervation of the DRL in patients with OA suggest that the DRL has an important proprioceptive and stabilizing role. CLINICAL RELEVANCE: Ligament innervation may correlate with proprioceptive and neuromuscular changes in OA pathophysiology and consequently support further investigation of innervation in disease prevention and treatment strategies.

Expander prosthesis and DIEP flaps in delayed breast reconstruction: Sensibility, patient-reported outcome, and complications in a five-year randomised follow-up study.

Breast reconstruction is a given choice for many women following mastectomy. There are a multitude of methods available today, and thus, comparative studies are essential to match patients with suitable methods. The aim of this study was to compare 5-year outcomes following delayed breast reconstruction with expander prosthesis (EP) and with deep inferior epigastric perforator (DIEP) flaps. Seventy-three patients, previously randomised to either a permanent EP or a DIEP flap breast reconstruction, were invited for a 5-year follow-up. Assessments included symmetry measurements, breast sensibility with Semmes-Weinstein monofilaments and patient-reported outcome (PRO) with the BREAST-Q. Complications within the first 5 postoperative years were recorded. Additionally, BREAST-Q questionnaires were collected from non-randomised patients with an EP breast reconstruction. Between 2019 and 2022, 65 patients completed the follow-ups. Symmetry and PRO were significantly higher in the DIEP flap group. However, EP-reconstructed breasts were significantly more sensate and demonstrated areas with protective sensibility, unlike the DIEP flap breasts. The overall complication rates were comparable between the two groups (p = 0.27). Regression analysis identified body mass index as a risk factor for reoperation in general anaesthesia and for wound infection. No significant differences were found in a comparison of the randomised and the non-randomised EP groups' BREAST-Q results. This randomised 5-year follow-up study found PRO to be favourable following a DIEP flap reconstruction and sensibility to be better in EP reconstructions. The complication rates were comparable; however, longer follow-ups are warranted to cover the complete lifespans of the two breast reconstruction methods.

Evaluation of an assessment scale for aesthetic outcome in breast reconstructions based on digital photos in both 2D and 3D format.

The aesthetic outcome is crucial in a breast reconstruction. Our aim was to evaluate the intra- and interrater reliability of an aesthetic outcome assessment scale with digital photos of breast reconstructions in two-dimensional (2D) and three-dimensional (3D) format. Thirty-three women with delayed breast reconstructions, consecutively participating in a five-year follow-up between November 2019 and June 2021, were included in the study. Of these, 14 were reconstructed with an expander prosthesis (EP) and 19 with a deep inferior epigastric perforator (DIEP) flap. Photos of the breasts were assessed in 2D and 3D format by expert, layman and patient panels. Data were analysed with the weighted kappa (wk) statistics. The intrarater agreements were moderate to substantial, with wk between 0.66 and 0.73 for the panels. Within the panels, the interrater agreements were 0.46-0.62. Moderate agreements were found between the matched 2D and 3D format photos (wk 0.62-0.66). The patient panel graded scar appearance worse in 3D compared with 2D format. In all panels, there was a tendency towards DIEP flap reconstructions receiving higher aesthetic outcome grades compared with EP. Thus, the aesthetic outcome assessment scale demonstrated acceptable agreements between the individual panellists and within the panels. Scars captured in 3D format may provide a greater resemblance to the reality compared with 2D. Implications for clinics remain to be further studied.

Scapular osseous free flap in head and neck reconstruction: An assessment of the postoperative function of the donor site.

BACKGROUND: The scapular osseous free flap (SOFF) has become an important reconstructive option for complex head and neck defects. Postoperative donor site function is, however, an important consideration. The objective of this study was to prospectively investigate SOFF donor site morbidity and to relate the findings to hand dominance and neck dissection. METHODS: Objective assessment included bilateral measurement of shoulder, elbow, and hand range of motion (ROM), hand strength, and distal nerve function in consecutive patients with head and neck cancer SOFF reconstruction at a tertiary referral center in Sweden between 2016 and 2019. The subjective function was assessed by the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. RESULTS: Sixteen of 20 consecutive patients were evaluated (median follow-up 10 months [range 3-17]). Significant side differences in shoulder range of motion (ROM) (flexion, abduction, external and internal rotation) were observed for patients where the SOFF had been harvested from the same side as their dominant hand (n = 9; Ps ≤ 0.04). For patients where the SOFF was harvested from the non-dominant hand side, no significant shoulder ROM side differences were observed (n = 7; Ps ≥ 0.08). There were significant side differences in shoulder ROM for patients who underwent neck dissections (n = 12; Ps ≤ 0.03), not for the other four patients. Patients reported low but varying DASH scores (median 2.5, range 0-57). CONCLUSION: Postoperative donor site morbidity seems to be quite acceptable after SOFF surgery. The results indicate possible benefits of choosing the non-dominant hand side for the SOFF and that a neck dissection affects postoperative shoulder outcome. Further studies are however needed.

Assessment of local tissue water in breasts following breast reconstruction with an expander prosthesis or DIEP flap.

The role of breast oedema in breast reconstruction is unknown. Therefore, our aim was to investigate local tissue water (LTW) and breast oedema-related symptoms in breasts reconstructed with either an expander prosthesis (EP) or with a deep inferior epigastric perforator (DIEP) flap at a minimum of one year postoperatively. Sixty-eight patients randomised to breast reconstruction with an EP or DIEP flap completed follow-up. Objective evaluation was performed at a mean of 25 (standard deviation, SD 9.5) months following breast reconstruction, and included measurements of breast volume and LTW with the MoistureMeterD® instrument. The patients completed the BREAST-Q questionnaire pre- and postoperatively. No significant differences in LTW were found when comparing EP and DIEP flap reconstructed breasts. The reconstructed breasts had an increase in LTW compared with the non-operated contralateral breasts. The BREAST-Q responses related to breast oedema symptoms were overall low and the median responses ranged from 1 to 2. A score of 1 indicated that symptoms were experienced 'None of the time'. Our findings indicate that mastectomy followed by breast reconstruction inflicts damage on the lymphatic system, shown as an increase in LTW. However, no breast oedema-related symptoms were reported in the BREAST-Q questionnaire, and therefore, we consider our objective results to be below a potential threshold for symptomatic breast oedema. A threshold for clinical indication of breast oedema remains to be defined.

Radical treatment of extensive nevoid hyperkeratosis of the areola and breast with surgical excision after mild response to topical agents: A case report.

INTRODUCTION: Nevoid hyperkeratosis of the nipple and/or areola (NHNA) is a benign lesion with a female predominance and an aesthetically disturbing appearance. Spontaneous remission is not reported and medical treatments proposed so far have shown variable results. PRESENTATION OF CASE: We describe a rare case of an extensive variant of NHNA covering almost the entire breasts' surface. At present, only three other reports are present in the literature. Medical treatment proved not completely effective and the patient was also affected by a significant breast asymmetry-hypertrophy. Therefore, NHNA was managed surgically with excision of the areolar affected portions while performing breast reduction-lift. The result was satisfactory and without recurrence of lesions at 5-year follow-up. DISCUSSION: This case reported favorable outcomes of surgery for NHNA. Reports of success with these procedures are still limited, but the promising results in terms of radicality and aesthetic outcome suggest it should be offered to patients as a viable therapeutic option. CONCLUSION: Indications for surgical treatment of NHNA can be: unsatisfying response to topical agents; young patients who want to restore the aesthetic appearance of the breast; and patients with concomitant indication for corrective surgery of the breast. Advantages are: predictable time of healing; predictable final result; radical excision of the affected tissue; and possibility of histologic analysis of the whole areola. In rare cases of lesions extending to the breast, preliminary treatment with topical agents can limit the extent of excision. Management and treatment should always be tailor-made for each individual case.

Trapeziometacarpal Ligaments Biomechanical Study: Implications in Arthroscopy.

Purpose In the presence of early osteoarthritis, changes to the trapeziometacarpal joint (TMJ) often result in pain and is associated with joint instability and a tendency of dorsoradial subluxation. In these instances, arthroscopy may be indicated to: (1) assess the extent of cartilage disease and the laxity of ligaments and to (2) treat TMJ instability. The purpose of our study was to biomechanically analyze which ligaments are the primary stabilizers of the TMJ. Methods Overall, 11 fresh-frozen human cadaver specimens were dissected and attached to a testing device with the thumb positioned in neutral abduction, neutral flexion, and neutral opposition. The four extrinsic and five intrinsic muscle tendons acting on the TMJ were simultaneously loaded with weights proportional to their physiological cross-sectional area. The dorsal, volar, and ulnar groups of ligaments were dissected. A motion-tracking device, FasTrak (Polhemus Inc., Colchester, VT), was used to study the spatial position of the base of the first metacarpal bone (MC1), before and after random sectioning of each of the ligaments. Statistical analysis of the MC1 translation along the transverse XY plane was performed using one-way analysis of variance and a paired t-test, with a significance level of p < 0.05. Results After isolated sectioning of the volar or the ulnar ligaments, the MC1 moved dorsoradially with an average of 0.150 mm (standard deviation [SD]: 0.072) and 0.064 mm (SD: 0.301), respectively. By contrast, the destabilization of the MC1 after sectioning of the dorsal ligaments was substantially larger (0.523 mm; SD: 0.0512; p = 0.004). Conclusion Sectioning of the dorsal ligament group resulted in the greatest dorsoradial translation of the MC1. Consequently, the dorsal ligaments may be regarded as the primary TMJ stabilizers. Clinical Relevance This study suggests that stabilizing arthroscopic shrinkage of the TMJ should be targeted toward the dorsal TMJ ligaments.

Altered Innervation Pattern in Ligaments of Patients with Basal Thumb Arthritis.

Purpose The population of mechanoreceptors in patients with osteoarthritis (OA) lacks detailed characterization. In this study, we examined the distribution and type of mechanoreceptors of two principal ligaments in surgical subjects with OA of the first carpometacarpal joint (CMC1). Methods We harvested two ligaments from the CMC1 of eleven subjects undergoing complete trapeziectomy and suspension arthroplasty: the anterior oblique (AOL) and dorsal radial ligament (DRL). Ligaments were divided into proximal and distal portions, paraffin-sectioned, and analyzed using immunoflourescent triple staining microscopy. We performed statistical analyses using the Wilcoxon Rank Sum test and ANOVA with post-hoc Bonferroni and Tamhane adjustments. Results The most prevalent nerve endings in the AOL and DRL of subjects with OA were unclassifiable mechanoreceptors, which do not currently fit into a defined morphological scheme. These were found in 11/11 (100%) DRLs and 7/11 (63.6%) AOLs. No significant difference existed with respect to location within the ligament (proximal versus distal) of mechanoreceptors in OA subjects. Conclusion The distribution and type of mechanoreceptors in cadavers with no to mild OA differ from those in surgical patients with OA. Where Ruffini endings predominate in cadavers with no to mild OA, unclassifiable corpuscles predominate in surgical patients with OA. These findings suggest an alteration of the mechanoreceptor population and distribution that accompanies the development of OA. Clinical Relevance Identification of a unique type and distribution of mechanoreceptors in the CMC1 of symptomatic subjects provides preliminary evidence of altered proprioception in OA.