Correlation of ulnar length and apoptotic cell death in degenerative lesions of the triangular fibrocartilage

Ulnar variance and triangular fibrocartilage thickness in adolescents: a cross-sectional MRI study of healthy participants

Skeletally immature wrists are considered at risk of injury due to increased axial loading through a relatively shorter ulna. The aim of this study was to determine whether triangular fibrocartilage thickness relates to ulnar variance and age in adolescents. The radiographs and MRIs of 24 healthy adolescents were retrospectively assessed. Four observers assessed bone age and ulnar variance on radiographs and measured triangular fibrocartilage thickness on MRIs. Median calendar and bone age was 13 years and ulnar variance was -0.7 mm. Median triangular fibrocartilage thickness was 1.4 mm, with excellent inter-observer agreement (r = 0.86). It was moderately correlated with ulnar variance (ρ = -0.46) as well as with bone age (ρ = -0.49). Both variables were statistically significant predictors in a multivariate analysis. This suggests that triangular fibrocartilage thickness changes during skeletal maturation, which might influence axial load distribution in skeletally immature wrists.

Long-term outcome after arthroscopic debridement of Palmer type 2C central degenerative lesions of the triangular fibrocartilage complex

PURPOSE

The purpose of this study was to report long-term objective and patient-reported outcome after arthroscopic debridement of central degenerative triangular fibrocartilage complex (TFCC) lesions.

METHODS

A total of 17 patients with central degenerative TFCC (Palmer type 2C) lesions and ulnar positive variance who were treated by arthroscopic debridement were retrospectively reviewed. Mean follow-up was 8.8 years. Assessment facilitating the Modified Mayo Wrist score (MMWS), the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH score), recording of pain level and of patient satisfaction, and radiological examination were done.

RESULTS

Patients reached a pain level of 1.7 VAS, MMW score of 92, and DASH score of 22. No significant differences could be detected between the operated and the contralateral extremity regarding range of motion and grip strength for all patients. No perioperative complications occurred.

CONCLUSION

Arthroscopic debridement of central degenerative TFCC lesions is safe, reliable, and efficacious even for ulnar positive variance.

LEVEL OF EVIDENCE

Therapeutic IV.

Degeneration of the articular disc in the human triangular fibrocartilage complex

INTRODUCTION

Traumatic injuries of the triangular fibrocartilage complex (TFCC) are frequent reasons for ulnar wrist pain. The assessment of the extent of articular disc (AD) degeneration is important for the differentiation of acute injuries versus chronic lesions.

MATERIALS AND METHODS

The AD of the TFCC of eleven human cadaver wrists was dissected. Degeneration was analyzed according to the grading of Krenn et al. Hematoxylin-eosin was used to determine the tissue morphology. Degeneration was evaluated using the staining intensity of alcian blue, the immunohistochemistry of the proteoglycan versican and the immunoreactivity of NITEGE, an aggrecan fragment.

RESULTS

The staining homogeneity of HE decreased with higher degeneration of the AD and basophilic tissue areas were more frequently seen. Two specimens were characterized as degeneration grade 1, five specimens as grade 2, and four specimens as grade 3, respectively. Staining intensity of alcian blue increased with higher degeneration grade of the specimens. Immunoreactivity for NITEGE was detected around tissue fissures and perforations as well as matrix splits. Immunoreactivity for versican was found concentrated in the tissue around matrix fissures and lesions as well as loose connective tissue at the ulnar border of the AD. Specimens with degeneration grade 2 had the strongest immunoreactivity of NITEGE and versican. Cell clusters were observed in specimens with degeneration grade 2 and 3, which were stained by alcian blue and immunoreactive for NITEGE and versican. Increasing age of the cadaver wrists correlated with a higher degree of degeneration (p < 0.0001, r = 0.68).

CONCLUSIONS

The fibrocartilage of degenerated ADs contains NITEGE and versican. The amount of the immunoreactivity of these markers allows the differentiation of degenerative changes into three grades. The degeneration of the AD increases with age and emphasizes its important mechanical function.

Narrative Review of Ligamentous Wrist Injuries

Ligamentous wrist injuries are common occurrences that require complex anatomical mastery and extensive understanding of diagnostic and treatment modalities. The purpose of this educational review article is to delve into the most clinically relevant wrist ligaments in an organized manner to provide the reader with an overview of relevant anatomy, function, clinical examination findings, imaging modalities, and options for management. Emphasis is placed on elucidating reported diagnostic accuracies and treatment outcomes to encourage evidence-based practice.

A Systematic Review of Outcomes after Arthroscopic Débridement for Triangular Fibrocartilage Complex Tear

BACKGROUND

Evidence regarding the effectiveness of arthroscopic débridement for a triangular fibrocartilage complex tear is uncertain. The purpose of this study was to conduct a systematic review of outcomes to evaluate the effectiveness of débridement for triangular fibrocartilage complex tears.

METHODS

The authors searched all available literature in the PubMed, Embase, and MEDLINE (Ovid) databases for articles reporting on triangular fibrocartilage complex tear débridement. Data collection included arc of motion, grip strength, patient-reported outcomes, and complications.

RESULTS

A total of 1723 unique studies were identified, of which 18 studies met the authors' criteria. The mean before and after arc of wrist extension/flexion motion values were 120 and 146 degrees (six studies). The mean before and after grip strength values were 65 percent and 91 percent of the contralateral side (10 studies). Disabilities of the Arm, Shoulder, and Hand scores (six studies) and pain visual analogue scale scores (seven studies) improved from 39 to 18, and from 7 to 3, respectively. The mean pain visual analogue scale score after débridement was 1.9 in the ulnar-positive group and 2.4 in the ulnar-neutral and ulnar-negative groups. Eighty-seven percent of patients returned to their original work.

CONCLUSIONS

Patients reported reduced pain and improved functional and patient-reported outcomes after débridement of triangular fibrocartilage complex tears. Most patients after débridement returned to previous work, with few complications. Although some of these cases may require secondary procedures, simple débridement can be performed with suitable satisfactory outcomes for cases with any type of ulnar variance.

Update TFCC: histology and pathology, classification, examination and diagnostics

The TFCC is a crucial stabilizer of the DRUJ. Based on its superficial and deep fibers, the TFCC guarantees unrestricted pronation and supination which is essential for performing sophisticated tasks. The ability to perform complex movements is of uppermost importance for hand function. Therefore, a functional intact TFCC is a prerequisite in this context. The articular disc of the TFCC is a fibrocartilaginous extension of the superficial zone of hyaline articular cartilage which arises from the radius. The peripheral 10-40 % of the TFC is vascularized. Degeneration of the articular disc is common with increasing age. Even though the central part of the articular disc is avascular, potential regeneration of lesions could be detected. The Palmer and Atzei classifications of TFCC lesions are complementary. TFCC innervation is based on different nerves. There is a high variability. A diligent clinical examination facilitates specific tests which help to allocate symptoms to the pathology. Therefore, a thorough clinical examination is not dispensable. Wrist arthroscopy remains the "gold standard" for diagnosing TFCC pathologies despite technical progress in imaging modalities. MR arthrography may have the potential to become a real alternative to wrist arthroscopy for diagnosing TFCC pathologies with technical progress in the future.

Functionality after arthroscopic debridement of central triangular fibrocartilage tears with central perforations

PURPOSE

To investigate functional and subjective outcome parameters after arthroscopic debridement of central articular disc lesions (Palmer type 2C) and to correlate these findings with ulna length.

METHODS

Fifty patients (15 men; 35 women; mean age, 47 y) with Palmer type 2C lesions underwent arthroscopic debridement. Nine of these patients (3 men; 6 women; mean static ulnar variance, 2.4 mm; SD, 0.5 mm) later underwent ulnar shortening osteotomy because of persistent pain and had a mean follow-up of 36 months. Mean follow-up was 38 months for patients with debridement only (mean static ulnar variance, 0.5 mm; SD, 1.2 mm). Examination parameters included range of motion, grip and pinch strengths, pain (visual analog scale), and functional outcome scores (Modified Mayo Wrist score [MMWS] and Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaire).

RESULTS

Patients who had debridement only reached a DASH questionnaire score of 18 and an MMWS of 89 with significant pain reduction from 7.6 to 2.0 on the visual analog scale. Patients with additional ulnar shortening reached a DASH questionnaire score of 18 and an MMWS of 88, with significant pain reduction from 7.4 to 2.5. Neither surgical treatment compromised grip and pinch strength in comparison with the contralateral side. We identified 1.8 mm or more of positive ulnar variance as an indication for early ulnar shortening in the case of persistent ulnar-sided wrist pain after arthroscopic debridement.

CONCLUSIONS

Arthroscopic debridement was a sufficient and reliable treatment option for the majority of patients with Palmer type 2C lesions. Because reliable predictors of the necessity for ulnar shortening are lacking, we recommend arthroscopic debridement as a first-line treatment for all triangular fibrocartilage 2C lesions, and, in the presence of persistent ulnar-sided wrist pain, ulnar shortening osteotomy after an interval of 6 months. Ulnar shortening proved to be sufficient and safe for these patients. Patients with persistent ulnar-sided wrist pain after debridement who had preoperative static positive ulnar variance of 1.8 mm or more may be treated by ulnar shortening earlier in order to spare them prolonged symptoms.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

How does ulnar shortening osteotomy influence morphologic changes in the triangular fibrocartilage complex?

BACKGROUND

Ulnar shortening osteotomy often is indicated for treatment of injuries to the triangular fibrocartilage complex (TFCC). However, the effect of ulnar shortening osteotomy on the changes in shape of the TFCC is unclear. In our study, quantitative evaluations were performed using MRI to clarify the effect of ulnar shortening on triangular fibrocartilage (TFC) thickness attributable to disc regeneration of the TFC and TFC angle attributable to the suspension effect of ulnar shortening on the TFC.

QUESTIONS/PURPOSES

The purposes of this study were (1) to compare preoperative and postoperative TFC thickness and TFC angle on MR images to quantitatively evaluate the effect of ulnar shortening osteotomy on disc regeneration and the suspension effect on the TFC; and (2) to assess whether changes in TFC thickness and TFC angle correlated with the Mayo wrist score.

METHODS

Between 1995 and 2008, 256 patients underwent ulnar shortening osteotomy for TFCC injuries. The minimum followup was 24 months (mean, 51 months; range, 24-210 months). A total of 79 patients (31%) with complete followup including preoperative and postoperative MR images and the Mayo wrist score was included in this retrospective study. Evaluation of the postoperative MR images and the Mayo wrist score were performed at the final followup. The remaining 177 patients did not undergo postoperative MRI, or they had a previous fracture, large tears of the disc proper, or were lost to followup. Two orthopaedists, one of whom performed the surgeries, measured the TFC thickness and the TFC angle on coronal MR images before and after surgery for each patient. Correlations of the percent change in the TFC thickness and the magnitude of TFC angle change with age, sex, postoperative MR images, extent of ulnar shortening, preoperative ulnar variance, and postoperative Mayo wrist score were assessed.

RESULTS

Stepwise regression analysis showed a correlation between the percent change in TFC thickness and preoperative ulnar variance (R2=0.21; β=-0.33; 95% CI, -0.11 to 0.01; p=0.01) and between the magnitude of change in the TFC angle and the extent of ulnar shortening (R2=0.18; β=-0.29; 95% CI, -5.8 to 0.29; p=0.03). The Mayo wrist score was not correlated with the percent change in TFC thickness or the magnitude of change in the TFC angle.

CONCLUSIONS

These results suggest that, in patients with TFCC injury with a smaller preoperative ulnar variance, a high residual potential for regeneration in the disc proper was seen after ulnar shortening osteotomy, and correlated with the extent of ulnar shortening and the suspension effect on TFC. However, there was no correlation between disc regeneration or the suspension effect on TFC and the Mayo wrist score.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Expression of leptin, leptin receptor, and connective tissue growth factor in degenerative disk lesions in the wrist

PURPOSE

The purpose of this study was to identify whether leptin and connective tissue growth factor (CTGF) occur in the degenerative fibrocartilage disk and whether cartilage cells express leptin receptors.

METHODS

The study included 23 patients diagnosed with degenerative articular disk tears of the triangular fibrocartilage (TFC) (Palmer type 2C). Patients were divided into 2 groups based on ulna length: 1 group consisted of patients with an ulna-positive variance (group A), and the other group included patients with ulna-negative or -neutral variance (group B). After arthroscopic debridement of the TFC, histologic sections of biopsy specimens were prepared. The biopsy specimens were immunohistochemically analyzed, and the quantity of leptin-, CTGF-, and leptin receptor-positive cells was assessed.

RESULTS

Cells positive for leptin, leptin receptor, and CTGF were found. The number of cells positive for leptin was significantly increased in specimens of patients with an ulna-negative variance (group B). In contrast, no significant difference was found for leptin receptor and CTGF in biopsy specimens of patients with ulna-positive or ulna-negative/neutral variance. The inner, middle, and outer zones of the disk do not express significantly different quantities of marker-positive cells.

CONCLUSIONS

Degenerative fibrocartilage disk tissue cells exhibit leptin receptors and are exposed to the markers leptin and CTGF, providing evidence of a local paracrine system and regenerative processes. Cells of disks from patients with an ulna-neutral/negative length express significantly higher numbers of leptin-positive cells.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Nerve fiber staining investigations in traumatic and degenerative disc lesions of the wrist

PURPOSE

Traumatic and degenerative disc lesions cause ulnar-sided wrist pain. To date, anatomical investigations of cadaver triangular fibrocartilage discs examining the innervation of the triangular fibrocartilage complex have found no evidence of nerve fibers in the healthy disc. In this study, we immunohistologically investigated biopsies from patients with either central traumatic or degenerative disc lesions, to determine the existence of nerve fibers. We hypothesized that an ingrowth of nerve fibers causes ulnar-sided wrist pain associated with traumatic and degenerative disc lesions.

METHODS

We included 32 patients with a traumatic Palmer 1A lesion and 17 patients with a degenerative Palmer 2C lesion in the study. We obtained a biopsy of each patient and stained the specimen with protein gene product 9.5 for nerve fiber detection.

RESULTS

There were no nerve fibers in either traumatic or degenerative disc lesions. In addition, the marginal areas of the biopsies showed no evidence of nerve fibers.

CONCLUSIONS

Traumatic and degenerative disc lesions show no ingrowth of nerve fibers.

Expression of TRAIL and death receptor DR4 in Palmer type 2 TFCC lesions

INTRODUCTION

Degenerative articular disc perforations of the triangular fibrocartilage (TFC) of the wrist are characterized by fibrocartilage cell loss and are often associated with ulna-plus situations. Apoptosis has been found to play a crucial role in fibrocartilage cell loss, however, the molecular mechanism and mediators are still poorly understood.

AIM

The purpose of this study was to identify receptors to apoptosis in degenerative disc lesions.

PATIENTS

Included in the study were 17 patients with degenerative articular disc tears of the TFC (Palmer type 2C). Following arthroscopic debridement of the TFC, histological sections were examined to assess the presence of apoptosis. Apoptosis was determined using TRAIL and death receptor DR4 agonists for immunohistochemical analyses. The number of cells positive for apoptosis was then correlated with ulna length.

RESULTS

Cells positive for TRAIL and DR4 were found in all specimens. The number of cells positive for TRAIL was significantly increased in specimens of patients with an ulna positive variance (P = 0.040). However, DR4 was not significantly increased in ulna plus (P > 0.05). Both, TRAIL and DR4 positive cells were found to be evenly distributed throughout each specimen. There was no accumulation of any type of cells in any particular zone of the biopsies.

CONCLUSION

This is the first study that shows that TFCC cells express TRAIL and DR4, which suggests that apoptosis, as well as, mechanical trauma are involved in the development of disc perforation. The TRAIL/DR4 receptor system is a molecular mediator of apoptosis induction in TFC cells and therefore plays a role in cell loss in degenerative disc lesions.

Cartilage cell proliferation in degenerative TFCC wrist lesions

INTRODUCTION

The central zone of the triangular fibrocartilage complex (TFCC) of the wrist is thought to be avascular and is generally considered to lack any healing potential.

AIM

The purpose of this study was to investigate, if cartilage cells of degenerative disc lesions possess any healing or proliferation potential and whether ulna length plays a significant role in the proliferation process.

RESULTS

Cells positive for proliferating cell nuclear antigen (PCNA) were found in all specimens. Specimens of patients with ulna positive variance showed a decreased number of PCNA positive cells than specimens of patients with either negative or neutral ulna variance.

CONCLUSION

We found that cartilage cells of Palmer type 2C lesions undergo mitotic cell division, thus exhibiting proliferation capability. It could not be shown that ulnar length is significantly correlated with the number of PCNA positive cells.

Ulnar shortening after TFCC suture repair of Palmer type 1B lesions

PURPOSE

The objective of this study was to determine functional and subjective outcomes of an ulnar shortening procedure elected by patients who experienced persistent ulno-carpal symptoms following arthroscopic suture repair of a Palmer type 1B lesion. All patients had a dynamic ulna positive variance.

METHODS

Five patients (3 males and 2 females) with arthroscopic repair of Palmer type 1B tears who subsequently underwent ulnar shortening were reviewed. At the time of the arthroscopic repair the patients' average age was 37 +/- 13 years (range 16-52 years). Average time to follow-up was 14 +/- 6 months (range 10-23 months). The average age was 38 +/- 14 years (range 17-53 years) when the ulnar shortening was performed. The second follow-up took place 7 +/- 2 months (range 5-9 months) after ulnar shortening. During the follow-ups, range of motion, grip strength, pain, Modified Mayo Wrist Score, DASH Score, and ulnar length were evaluated. Citing persistent ulno-carpal symptoms, the patients elected ulnar shortening an average of 17 +/- 7months (range 13-29 months) following the arthroscopic repair. Prior to ulnar shortening the average static ulnar variance was 0.2 +/- 1.3 mm (range -1 to 2 mm), the average dynamic ulnar variance was 1.4 +/- 0.5 mm (range 1 to 2 mm).

RESULTS

Ulnar shortening brought about further reduction in pain after the arthroscopic repair of the triangular fibrocartilage complex (TFCC) had already reduced it. As measured by a visual analogue scale, the average value after ulnar shortening was 2.2 +/- 2.1 (range 0.7-5.0). The average static ulnar variance was -3.4 +/- 2 mm (range -5 to -1 mm). Patients were very satisfied with the results of the ulnar shortening and four out of five indicated that it had significantly improved their symptoms and they would elect ulnar shortening again. Postoperative range of motion as a percentage of the contralateral side averaged 90% for the extension/flexion arc, 80% for the radial/ulnar deviation arc, and 100% for the pronation/supination arc of motion. In addition, there was an improvement in grip strength. The Modified Mayo Wrist Score was rated excellent in three patients, and fair in two patients. The average DASH score was 22 +/- 22 (range 0-53).

CONCLUSIONS

Patients who have a dynamic ulna positive variance and experience persistent ulno-carpal symptoms following arthroscopic suture repair of a Palmer type 1B lesion, benefit from an ulnar shortening procedure. Shortening the ulna can improve these patients' symptoms of pain, range of motion, and grip strength.

Apoptotic pathways in degenerative disk lesions in the wrist

PURPOSE

Degenerative articular disk perforations of the triangular fibrocartilage (TFC) of the wrist could result from chronic loading of the ulnocarpal joint. Apoptosis played a crucial role in fibrocartilage cell loss, and the purpose of this study was to clarify which apoptotic pathway was involved in the development of degenerative disk lesions. We also investigated whether ulna length played an etiologic role in the occurrence of fibrocartilage cell loss.

METHODS

Included in the study were 17 patients with degenerative articular disk tears of the TFC (Palmer type 2C). After arthroscopic debridement of the TFC, histologic sections were examined to assess the presence of apoptosis. Apoptosis was determined by use of caspase 3, caspase 8, and caspase 9 immunohistochemistry. Furthermore, Fas ligand and BID (BH3 interacting domain death) agonist were applied for immunohistochemical analysis.

RESULTS

Cells positive for caspase 3, caspase 8, caspase 9, Fas ligand, and BID were found in all specimens. The number of cells positive for caspase 3 and BID was significantly increased in specimens from patients with an ulna-positive variance. In contrast, for cells positive for caspase 8, caspase 9, and Fas ligand, no significant difference was found between specimens from patients with an ulna-positive variance and those from patients with an ulna-neutral/ulna-negative variance.

CONCLUSIONS

The extrinsic and intrinsic apoptotic pathways are involved in the development of degenerative disk lesions. Fibrocartilage cell loss occurs mainly through the intrinsic apoptotic pathway. The accumulation of apoptotic cells is not significantly different between the 3 zones of the TFC. It could be verified that ulna length is correlated with fibrocartilage cell loss.

CLINICAL RELEVANCE

Ulnar shortening is a valuable treatment option for degenerative TFC lesions. Knowledge of the specific apoptotic pathway that is causing degenerative disk lesions is critical in selecting the appropriate and most beneficial therapeutic treatment to halt further cell loss and the degeneration of the TFC.

Incidence and distribution of blood vessels in punch biopsies of Palmer 1A disc lesions in the wrist

INTRODUCTION

Although the partial excision of triangular fibrocartilage complex (TFCC) tears appears to be a clinically effective technique, little is known about the ability of the central disc tears to heal. Unlike peripheral tears, central tears do not have immediate access to blood supply. The purpose of this study was to examine the incidence and distribution of blood vessels in punch biopsies of symptomatic central TFCC tissue. In addition, the study investigated if arthroscopic debridement can reach vascularized tissue to enable a reparative response of the tear.

MATERIALS AND METHODS

Thirty-two patients with symptomatic central traumatic tears in the TFCC (Palmer 1A) were included in this study. The cartilage was debrided arthroscopically using a biopsy punch. The debrided tissue was then examined histologically. To visualize blood vessels, the histological sections were stained with CD 31 antibodies. The presence/absence of blood vessels was recorded on a qualitative level.

RESULTS

In six patients, five or more blood vessels (CD31 positive endothelial cells) could be detected. In eight patients, fewer than five vessels could be found in the periphery of the slides. In 18 patients no vessels could be identified. The incidence of vessels in the outer region was higher than in the inner region of the peripheral area. There was no correlation found between the time of trauma and incidence of blood vessels (P > 0.05).

CONCLUSION

Only in 43% of arthroscopic debridements of Palmer 1A tears vascularized tissue could be reached.

Arthroscopic repair of Palmer 1B triangular fibrocartilage complex tears

PURPOSE

The objective of this retrospective study was to determine functional and subjective outcomes of patients with Palmer type 1B tears repaired arthroscopically and to investigate whether clinical outcomes are related to ulna length.

METHODS

Forty-six patients with arthroscopic repair of Palmer type 1B tears were reviewed. There were 23 males and 23 females. The average age was 34 years (range, 10 to 58 yrs). The average follow-up was 11 months (range, 6 to 23 mos), and the delay to surgery was 9.7 months. All patients suffered ulnar-sided wrist pain and were diagnosed with Palmer type 1B tears. The tear was repaired arthroscopically with an inside-outside suture technique. The range of motion (ROM), grip strength, pain, wrist score (modified Mayo wrist score), Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) score, and ulna length (static and dynamic) were evaluated.

RESULTS

There was a reduction in pain and an improvement in grip strength. Postoperative ROM averaged 128 degrees +/- 23 degrees for the extension/flexion arc, 41 degrees +/- 11 degrees for the radial/ulnar deviation arc, and 171 degrees +/- 19 degrees for the pronation/supination arc of motion. However, no relation could be found between ulna length and clinical outcome. The modified Mayo wrist score was rated excellent in 22% of patients, good in 41%, fair in 27%, and poor in 10%. The average DASH score was 21.70 +/- 17.17 (range, 0 to 58.33).

CONCLUSIONS

Arthroscopic repair of Palmer type 1B tears yields satisfactory results. Sixty-three percent of patients achieved good to excellent results, experienced increased ROM, grip strength, and pain relief. Ulnar neutral or positive variance is not a contraindication for suture repair and does not require simultaneous ulna shortening when repairing the triangular fibrocartilage complex arthroscopically. A delay to surgery did not affect clinical outcome.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.