Cementless reverse total shoulder arthroplasty implantation with humeral matchstick autograft augmentation: early radiographic outcomes.

BACKGROUND: Humeral-sided complications account for up to 21% of all revision reverse total shoulder arthroplasty (RTSA) surgeries. Stress shielding with large bulky stems can lead to proximal bone resorption per Wolff law, complicating further surgeries. Previously published studies suggest that lowering the metaphyseal implant fill ratio can lead to fewer adaptive radiographic changes and decreased bone resorption. Inspired by these studies, cementless primary RTSA implantation technique with humeral matchstick autografts was proposed to augment cementless humeral constructs, foster the use of a smaller size stem, and create primary stability of the humeral implant even in osteoporotic or in-between size medullary canals. In this study, retrospective review of this cementless RTSA technique with short-term radiographic evaluation was performed. METHODS: Forty-six nonconsecutive patients underwent primary RTSA with a short-stem cementless prosthesis (Stryker Ascend Flex) augmented by matchstick bone grafting from January to July 2020. Patient demographics were recorded, and follow-up radiographs were retrospectively reviewed to assess metaphyseal fill ratios and incidence of stress shielding at minimum 1-year follow-up. Discrepancies between templated and final stem sizes were recorded, along with all intraoperative and postoperative complications. RESULTS: Of the 46 patients originally identified, there were 5 men and 41 women with a mean age of 71 years (standard deviation [SD] 7, range 53-88). Mean templated stem size was 4 (SD 2, range 1-8), whereas the mean final implant size was 2 (SD 1, range 1-3). Mean fill ratios were 0.76 (SD 0.06, range 0.54-0.89) along the metaphysis and 0.67 (SD 0.09, range 0.49-0.83) along the diaphysis. There were no intraoperative humeral fractures from implantation. All patients were available for radiographic follow-up with a mean of 19 months (SD 8, range 12-40). There were 3 cases (7%) of proximal humeral stress shielding, with average fill ratios of 0.857 and 0.807 in the metaphysis and diaphysis, respectively. There were 3 patients (7%) who underwent revision surgeries for baseplate failure and periprosthetic humeral fracture. There were no cases of early humeral loosening. DISCUSSION: Matchstick autograft humeral augmentation is a simple, promising surgical technique with low intraoperative complication rates and good short-term radiographic outcomes. When the implant fill ratio is successfully reduced, there is a possible lower risk of humeral stress shielding. The authors believe this technique can help maximize implant stability in cementless shoulder arthroplasty and preserve humeral bone stock for future revision surgeries.

Bio-monitoring of DNA damage in matchstick industry workers from Peshawar Khyber Pakhtunkhwa, Pakistan.

BACKGROUND: Safety protocols are usually neglected in most of the matchstick industries rendering the laborer prone to various occupational hazards. OBJECTIVE: The present study highlights DNA damage among matchstick factory workers (n = 92) against a control group (n = 48) of healthy individuals. METHODS: Genotoxicity was measured in peripheral blood lymphocytes of the test subjects using a Single Cell Gel Electrophoresis assay (SCGE/comet assay). RESULTS: Our results substantiate a high Total Comet Score (TCS) for factory workers (74.5 ± 47.0) when compared to the control group (53.0 ± 25.0) (P ≤ 0.001). Age and duration of occupational exposure had no significant effect (P > 0.05) on TCS value. As for job function, the TCS value was greatest in sweepers (91.0 ± 56.1) and lowest in box-making operators (26.0 ± 25.0) indicating that waste disposal poses the higher risk of DNA damage. CONCLUSIONS: Our study corroborates that matchstick chemicals can potentially damage the DNA of exposed subjects.

Summer egg diapause in a matchstick grasshopper synchronizes the life cycle and buffers thermal extremes.

The phenological response is among the most important traits affecting a species' sensitivity to climate. In insects, strongly seasonal environments often select for a univoltine life cycle such that one seasonal extreme is avoided as an inactive stage. Through understanding the underlying mechanisms for univoltinism, and the consequences of its failure, we can better predict insect responses to climate change. Here we combine empirical data and simulation studies to investigate the consequences of an unusual diapause mechanism in a parthenogenetic matchstick grasshopper, Warramaba virgo, from arid southern Australia. Our field body temperature measurements indicate that this species is a thermoconformer and our laboratory studies of the thermal response of feeding rate imply strong constraints on winter activity. However, the species exhibits no obligate winter diapause, and eggs can develop in 1 month under constant temperatures approximating the mean soil temperature at the time of oviposition (summer). We show that diurnal temperature cycles exceeding a peak of 36 °C inhibit egg development in summer, and that this is sufficient to prevent autumnal hatching of eggs. Development is also strongly retarded below 24 °C. Microclimate-driven simulation studies of egg development show that these thermal responses provide robust maintenance of a univoltine life cycle, thereby resulting in survival of heat stress as an egg (due to limited developmental state) and avoidance of cold stress as a nymph and adult (due to overwintering in the soil as an egg).

Clavicle Nonunion: Matchstick Bone-grafting and Osteosynthesis

BACKGROUND: This study was conducted to evaluate the surgical outcomes of plate fixation using autologous iliac bone graft shaped in the form of a matchstick in clavicle nonunion resulting from prior surgical or non-surgical management. METHODS: From May 2005 to February 2013, 17 patients underwent surgery for clavicle nonunion. The mean age at the time of surgery was 48.8 years. The iliac bone was harvested and shaped into slivers approximately 3 cm long, which resembled matchsticks. After opening of the medullary canal, the plate and screws were applied and cancellous bone was placed at the nonunion site. Matchstick bone grafts which were longitudinally placed and encircled on the nonunion site were tied with periosteum using 3–4 stitches. Union was determined via postoperative plane X-ray. Clinical status was evaluated using the visual analogue scale score for pain, and Constant and American Shoulder Elbow Surgeon score. RESULTS: All patients had a stable radiological union at the follow-up. The mean duration from index operation to nonunion operation was 13.2 months (7–32 months). The mean follow-up period was 20.1 months (8–56 months), and the mean duration until union was 11.2 weeks (8–16 weeks). All clinical scores were improved at the final follow-up (p<0.001). The mean segmental defect was 3.3 ± 2.6 mm (1–18 mm); and the difference in clavicular length between operative and non-operative site was 5.9 ± 6.9 mm. CONCLUSIONS: Matchstick shaped autologous iliac bone grafting technique in clavicle nonunion is acceptable with a high union rate.

Clavicle Nonunion: Matchstick Bone-grafting and Osteosynthesis

BACKGROUND: This study was conducted to evaluate the surgical outcomes of plate fixation using autologous iliac bone graft shaped in the form of a matchstick in clavicle nonunion resulting from prior surgical or non-surgical management. METHODS: From May 2005 to February 2013, 17 patients underwent surgery for clavicle nonunion. The mean age at the time of surgery was 48.8 years. The iliac bone was harvested and shaped into slivers approximately 3 cm long, which resembled matchsticks. After opening of the medullary canal, the plate and screws were applied and cancellous bone was placed at the nonunion site. Matchstick bone grafts which were longitudinally placed and encircled on the nonunion site were tied with periosteum using 3–4 stitches. Union was determined via postoperative plane X-ray. Clinical status was evaluated using the visual analogue scale score for pain, and Constant and American Shoulder Elbow Surgeon score. RESULTS: All patients had a stable radiological union at the follow-up. The mean duration from index operation to nonunion operation was 13.2 months (7–32 months). The mean follow-up period was 20.1 months (8–56 months), and the mean duration until union was 11.2 weeks (8–16 weeks). All clinical scores were improved at the final follow-up (p<0.001). The mean segmental defect was 3.3 ± 2.6 mm (1–18 mm); and the difference in clavicular length between operative and non-operative site was 5.9 ± 6.9 mm. CONCLUSIONS: Matchstick shaped autologous iliac bone grafting technique in clavicle nonunion is acceptable with a high union rate.

Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion.

We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ∼5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose chronic exposure. This case represents possible sequelae of chronic potassium chlorate ingestion.

Matchstick-Shaped Bone Grafting for the Treatment of Distal Phalangeal Nonunion

PURPOSE: The purpose of this study was to evaluate clinical and radiological results after osteosynthesis of distal phalangeal nonunion with bone defect by using matchstick-shaped bone graft. MATERIALS AND METHODS: Fifteen distal phalangeal nonunions were treated with osteosynthesis using matchstick-shaped bone graft from September, 2009 to October, 2010. The mean age of patients was 36.1 years (range: 15 to 56 years). This study included 4 women and 10 men. The mean duration of follow-up was 16.8 months (range: 12 to 20 months). We evaluated radiographs, and measured postoperative visual analogue scale (VAS) score and pinch power. RESULTS: Union was achieved in all cases at a mean of postoperative 5.5 weeks (range: 4 to 6 weeks). The mean VAS score improved from 7.25 (range: 5 to 9) to 1.0 (range: 0 to 2) postoperatively. The mean postoperative pinch power was 7.75 lbs (range: 4 to 13 lbs) compared to opposite pinch power of 9.63 lbs (range: 5 to 15 lbs). There was no scar problem, pinch pain and other complication. CONCLUSION: Steosynthesis of distal phalageal nonunion with bone defect by using matchstick-shaped bone graft is technically feasible and simple in that it does not need volar incision and debridement. It is considered as an effective treatment option in distal phalangeal nonunion with bone defect.