Small Studies Back Injections for Tennis Elbow

MONTREAL — Four different injection therapies appear to be effective for refractory lateral epicondylosis (tennis elbow) and offer additional treatment options for patients who have failed conservative care, suggest results of a systematic review.

“We know that 80% of these injuries get better on their own, but for the ones that don't, these injection therapies make sense,” Dr. David Rabago said at the annual meeting of the North American Primary Care Research Group.

Dr. Rabago of the University of Wisconsin, Madison, reviewed the evidence for prolotherapy, polidocanol injection, autologous whole-blood injection, and platelet-rich plasma injection therapies (Br. J. Sports Med. 2009;43:471–81).

Out of 21 possible studies, 9 studies met inclusion criteria: 5 prospective case series and 4 controlled trials. Three studies focused on prolotherapy, two on polidocanol injection, three on autologous whole-blood injection, and one on platelet-rich plasma injection.

The total number of patients in all studies combined was 201, and they ranged in age from 19 to 66 years old. Refractory elbow pain ranged anywhere from 3 to 25 months, and the follow-up periods ranged from 9 to 108 weeks.

Reduced pain was the primary outcome of each study, rated according to a visual analog scale or pain questionnaire. Improvement from baseline or compared with controls ranged from 51% to 94%, said Dr. Rabago. Secondary outcomes, which included elbow function and a decrease in abnormalities or vascularity on ultrasound, also showed improvement in all studies.

These moderate to large effect sizes were sustained over 12–25 months, and “far exceed minimal clinically relevant effect sizes for chronic pain,” said Dr. Rabago.

There were no adverse events reported.

Polidocanol is a vascular sclerosant that is injected into areas of high intratendinous blood flow in the elbow, using high-resolution ultrasound and color Doppler visualization. Its mechanism of action is believed to be the interruption of neovascular pathology, which is associated with pain and degeneration. Polidocanol is the most commonly used therapy worldwide, but is not available in the United States.

Prolotherapy also involves the injection of vascular sclerosants (most often hyperosmolar dextrose or morrhuate sodium), but does not require ultrasound guidance.

Autologous whole blood involves drawing blood from the patient and injecting it into the painful area to trigger a healing response.

Platelet-rich plasma is centrifuged from autologous whole blood and injected into the painful area to trigger healing with platelet-derived growth factors.

While prolotherapy is the easiest of the four therapies to implement, the reviewed studies showed that it required three treatment sessions, compared with the one or two sessions needed for the other therapies, Dr. Rabago noted.

With some basic training and equipment, all four therapies can be performed in a family medicine office on an outpatient basis, Dr. Rabago said in an interview.

“Each of the studies reviewed is small, and their methodological limitations prevent a consensus recommendation on the use of any of the three therapies, compared with another, at this time. However, the large effect sizes reported by all studies are compelling and suggest several areas of clinical, theoretical, and research interest,” wrote Dr. Rabago and his coauthors in their paper.

One of Dr. Rabago's coauthors is a consultant and lecturer for Harvest Technologies, a manufacturer of centrifuge and ancillary equipment for platelet-rich plasma injection therapy. Harvest had no direct or indirect role in the study. No other coauthor reported any conflict of interest.

MONTREAL — Four different injection therapies appear to be effective for refractory lateral epicondylosis (tennis elbow) and offer additional treatment options for patients who have failed conservative care, suggest results of a systematic review.

“We know that 80% of these injuries get better on their own, but for the ones that don't, these injection therapies make sense,” Dr. David Rabago said at the annual meeting of the North American Primary Care Research Group.

Dr. Rabago of the University of Wisconsin, Madison, reviewed the evidence for prolotherapy, polidocanol injection, autologous whole-blood injection, and platelet-rich plasma injection therapies (Br. J. Sports Med. 2009;43:471–81).

Out of 21 possible studies, 9 studies met inclusion criteria: 5 prospective case series and 4 controlled trials. Three studies focused on prolotherapy, two on polidocanol injection, three on autologous whole-blood injection, and one on platelet-rich plasma injection.

The total number of patients in all studies combined was 201, and they ranged in age from 19 to 66 years old. Refractory elbow pain ranged anywhere from 3 to 25 months, and the follow-up periods ranged from 9 to 108 weeks.

Reduced pain was the primary outcome of each study, rated according to a visual analog scale or pain questionnaire. Improvement from baseline or compared with controls ranged from 51% to 94%, said Dr. Rabago. Secondary outcomes, which included elbow function and a decrease in abnormalities or vascularity on ultrasound, also showed improvement in all studies.

These moderate to large effect sizes were sustained over 12–25 months, and “far exceed minimal clinically relevant effect sizes for chronic pain,” said Dr. Rabago.

There were no adverse events reported.

Polidocanol is a vascular sclerosant that is injected into areas of high intratendinous blood flow in the elbow, using high-resolution ultrasound and color Doppler visualization. Its mechanism of action is believed to be the interruption of neovascular pathology, which is associated with pain and degeneration. Polidocanol is the most commonly used therapy worldwide, but is not available in the United States.

Prolotherapy also involves the injection of vascular sclerosants (most often hyperosmolar dextrose or morrhuate sodium), but does not require ultrasound guidance.

Autologous whole blood involves drawing blood from the patient and injecting it into the painful area to trigger a healing response.

Platelet-rich plasma is centrifuged from autologous whole blood and injected into the painful area to trigger healing with platelet-derived growth factors.

While prolotherapy is the easiest of the four therapies to implement, the reviewed studies showed that it required three treatment sessions, compared with the one or two sessions needed for the other therapies, Dr. Rabago noted.

With some basic training and equipment, all four therapies can be performed in a family medicine office on an outpatient basis, Dr. Rabago said in an interview.

“Each of the studies reviewed is small, and their methodological limitations prevent a consensus recommendation on the use of any of the three therapies, compared with another, at this time. However, the large effect sizes reported by all studies are compelling and suggest several areas of clinical, theoretical, and research interest,” wrote Dr. Rabago and his coauthors in their paper.

One of Dr. Rabago's coauthors is a consultant and lecturer for Harvest Technologies, a manufacturer of centrifuge and ancillary equipment for platelet-rich plasma injection therapy. Harvest had no direct or indirect role in the study. No other coauthor reported any conflict of interest.

MONTREAL — Four different injection therapies appear to be effective for refractory lateral epicondylosis (tennis elbow) and offer additional treatment options for patients who have failed conservative care, suggest results of a systematic review.

“We know that 80% of these injuries get better on their own, but for the ones that don't, these injection therapies make sense,” Dr. David Rabago said at the annual meeting of the North American Primary Care Research Group.

Dr. Rabago of the University of Wisconsin, Madison, reviewed the evidence for prolotherapy, polidocanol injection, autologous whole-blood injection, and platelet-rich plasma injection therapies (Br. J. Sports Med. 2009;43:471–81).

Out of 21 possible studies, 9 studies met inclusion criteria: 5 prospective case series and 4 controlled trials. Three studies focused on prolotherapy, two on polidocanol injection, three on autologous whole-blood injection, and one on platelet-rich plasma injection.

The total number of patients in all studies combined was 201, and they ranged in age from 19 to 66 years old. Refractory elbow pain ranged anywhere from 3 to 25 months, and the follow-up periods ranged from 9 to 108 weeks.

Reduced pain was the primary outcome of each study, rated according to a visual analog scale or pain questionnaire. Improvement from baseline or compared with controls ranged from 51% to 94%, said Dr. Rabago. Secondary outcomes, which included elbow function and a decrease in abnormalities or vascularity on ultrasound, also showed improvement in all studies.

These moderate to large effect sizes were sustained over 12–25 months, and “far exceed minimal clinically relevant effect sizes for chronic pain,” said Dr. Rabago.

There were no adverse events reported.

Polidocanol is a vascular sclerosant that is injected into areas of high intratendinous blood flow in the elbow, using high-resolution ultrasound and color Doppler visualization. Its mechanism of action is believed to be the interruption of neovascular pathology, which is associated with pain and degeneration. Polidocanol is the most commonly used therapy worldwide, but is not available in the United States.

Prolotherapy also involves the injection of vascular sclerosants (most often hyperosmolar dextrose or morrhuate sodium), but does not require ultrasound guidance.

Autologous whole blood involves drawing blood from the patient and injecting it into the painful area to trigger a healing response.

Platelet-rich plasma is centrifuged from autologous whole blood and injected into the painful area to trigger healing with platelet-derived growth factors.

While prolotherapy is the easiest of the four therapies to implement, the reviewed studies showed that it required three treatment sessions, compared with the one or two sessions needed for the other therapies, Dr. Rabago noted.

With some basic training and equipment, all four therapies can be performed in a family medicine office on an outpatient basis, Dr. Rabago said in an interview.

“Each of the studies reviewed is small, and their methodological limitations prevent a consensus recommendation on the use of any of the three therapies, compared with another, at this time. However, the large effect sizes reported by all studies are compelling and suggest several areas of clinical, theoretical, and research interest,” wrote Dr. Rabago and his coauthors in their paper.

One of Dr. Rabago's coauthors is a consultant and lecturer for Harvest Technologies, a manufacturer of centrifuge and ancillary equipment for platelet-rich plasma injection therapy. Harvest had no direct or indirect role in the study. No other coauthor reported any conflict of interest.