Platelet-rich plasma vs. steroid injections for hamstring injury-is there really a choice?

OBJECTIVE: To assess the effectiveness of pain relief in patients with grade 2 proximal hamstring injury, treated with platelet-rich plasma (PRP) or corticosteroid injection, by using the primary outcome of visual analog scale (VAS) at 1 week and 4 weeks of follow-up. MATERIALS AND METHODS: A single institution retrospective study was performed for image-guided PRP or steroid injections between 12/1/2015 and 10/30/2017 for proximal hamstring injuries. VAS was measured at 1 week and 4 weeks post-injection via telephone interviews and the pain response was recorded into two groups (negative/no change vs. positive). A comparison of pain responses between PRP and steroid was conducted by generalized estimating equation. RESULTS: Among 56 patients, 32 received PRP and 24 received steroid injections with ages from 13 to 75 years old. At 1 week post-injection follow-up, 23 patients (71.9%) from the PRP group and 11 patients (45.8%) from the steroid group showed positive response. After controlling for age, pre-procedure pain level, and gender, the positive response rate in the PRP group was higher than the steroid group (aOR: 4.04, 95% CI: 1.04-15.63, p value = 0.04). At 4 weeks post-injection, 23 patients (71.9%) from the PRP group and 13 patients (54.2%) from the steroid group showed positive response with no statistical significance (aOR: 2.48, 95% CI: 0.63-9.79, p value = 0.19). CONCLUSIONS: The PRP group had shown more favorable response compared to steroid group at 1 week post-injection, which suggests that PRP therapy can be considered as a conservative treatment choice for grade 2 proximal hamstring injuries with better short-term pain relief based on limited pilot data.

Effects of pressure applied during standardized spinal mobilizations on peripheral skin blood flow: A randomised cross-over study.

BACKGROUND: Peripheral skin blood flow (SBF) changes during and after spinal mobilization (SM), evaluated with laser Doppler flowmetry, may document physiological responses associated with SM. OBJECTIVES: To document variations in SBF during and after application of an SM and evaluate influence of pressure on SBF by applying the same standardized SM with 3 different nonnoxious pressures. DESIGN: Cross-over design with 4 interventions on 4 different days: control (no touch) and 3 SMs applied rhythmically at 5%, 40%, or 80% of pain pressure threshold (sham SM, low-pressure SM, or high-pressure SM, respectively). METHOD: Thirty-two individuals participated. The inspiratory gasp (IG) test was our positive control of vasoconstriction through excitation of the skin sympathetic nervous activity (SSNA). Each session comprised 5 phases: (1) baseline at the end of a 20-min acclimatization, (2) IG test, (3) post-IG phase, (4) SM phase or no manual contact for control, and (5) post-SM phase. A Biopac MP36 system collected SBF data, and a Novel Pliance-X system recorded pressure data. RESULTS/FINDINGS: Equal and significant bilateral vasodilation occurred during application of unilateral sham SM, low-pressure SM, and high-pressure SM. Post-SM significant vasodilation persisted after high-pressure SM. CONCLUSIONS: The current study is the first to describe bilateral peripheral SBF changes occurring during and 5 min after application of standardized SMs. Our post-SM vasodilation suggests involvement of mechanisms other than the putative SSNA-excitatory mechanism proposed with skin conductance measurements. Persistence of post-SM vasodilation following only high-pressure SM suggests possible pressure-dependent mechanisms. However, further research is warranted to clarify our findings.

Assessment of skin blood flow following spinal manual therapy: a systematic review.

Skin blood flow (SBF) indexes have been used to describe physiological mechanisms associated with spinal manual therapy (SMT). The aims of the current review were to assess methods for data collection, assess how investigators interpreted SBF changes, and formulate recommendations to advance manual medicine research. A database search was performed in PubMed, Cochrane Library, the Physiotherapy Evidence Database, and the Cumulative Index to Nursing and Allied Health Literature through April 2014. Articles were included if at least 1 outcome measure was changes in 1 SBF index following SMT. The database search yielded 344 records. Two independent authors applied the inclusion criteria. Twenty studies met the inclusion criteria. Selected studies used heterogeneous methods to assess short-term post-SMT changes in SBF, usually vasoconstriction, which was interpreted as a general sympathoexcitatory effect through central mechanisms. However, this conclusion might be challenged by the current understanding of skin sympathetic nervous activity over local endothelial mechanisms that are specifically controlling SBF. Evaluation of SBF measurements in peripheral tissues following SMT may document physiological responses that are beyond peripheral sympathetic function. Based on the current use of SBF indexes in clinical and physiological research, 14 recommendations for advancing manual medicine research using laser Doppler flowmetry are presented.

Laser Doppler flowmetry in manual medicine research.

Laser Doppler flowmetry (LDF) is commonly used in combination with reactivity tests to noninvasively evaluate skin sympathetic nerve activity and skin microvascular function. In manual medicine research, LDF has been used as a marker for global peripheral sympathetic nervous system function, but these results should be considered with caution because skin sympathetic nerve activity physiology is often overlooked. Another limitation of LDF in manual medicine research is the processing of LDF recordings. Two methods have been suggested: the time-domain analysis and the frequency-domain analysis. Standardization is required for data collection and processing in either domain to accurately interpret these changes in skin blood flow that occur after manual procedures. For physiologic studies using LDF, the authors recommend the use of noninvasive reactivity tests (positive controls) to evaluate the different mechanisms involved in overall skin blood flow changes and to compare the magnitude of these changes with those specifically elicited by manual procedures.