Table 9: Single injection femoral nerve block versus placebo/no treatment/systemic analgesia: study details and qualitative outcomes

Study

n treatment/
control

Comparison

Supplemental

analgesic

VAS scores and type of pain, where specified

Time to first analgesic request

Use of supplemental analgesic

Other important outcomes

Hirst 1996(LoE 1)

11/11

Pre-op single injection femoral nerve block with 20 ml 0.5% bupivacaine and 1:200,000 epinephrine (Fem) vs. “mock” femoral nerve blocks (Cont)

Postop: PCA-morphine, IV

Fem superior during passive flexion (30°) in recovery room (p<0.05); NS at other time points recorded (i.e. in the next 72 h)

__

Morphine requirements: NS during assessment period (i.e. over 1^st 48 h postop)

PONV

Nausea: Fem superior at 24 and 48 h (p values not reported)

Macalou 2004

(LoE 1)

29/28

Before induction of GA: femoral nerve block with 0.5% bupivacaine and 2% lidocaine (25 ml of LA solution injected) with 1:200,000 epinephrine (Fem) vs. 10 ml saline at site of femoral nerve (Cont)

Postop: PCA-morphine, IV

NS during assessment period (i.e. 1^st 6 h postop)

__

NS during assessment period (i.e. 1^st 6 h postop)

PONV

NS

Complications

Respiratory depression: NS

Szczukowski 2004

(LoE 1)

19/21

Pre-op single injection femoral nerve block with 30 ml 0.5% bupivacaine and 1:200,000 epinephrine (Fem) vs. sham femoral nerve block with 30 ml saline (Cont)

Postop: PCA-morphine, IV; 5 mg oral oxycodone or 325 mg oral acetaminophen available every 4 h if required

Fem superior on day of surgery (day 0), (p=0.002), but NS on days 1 and 2; average pain score (days 0–2): Fem superior (p=0.013)

__

Morphine consumption: Fem superior on day 1 (p=0.003) and over the entire postop period (i.e. over days 0–3) (p=0.011)

PONV

NS

Functional outcomes

Degree of ambulation, ROM: NS

Complications

Sedation: Fem superior on day 1 (p=0.045), but NS on days 2 and 3; pruritus, urinary retention, dizziness: NS

Hospital stay

Length of hospital stay: NS

YaDeau 2005

(LoE 1)

41/39

Pre-op :30 ml 0.375% bupivacaine with 5 µg/ml epinephrine into femoral sheath (Fem) vs. control (Cont)

Background analgesia: spinal-epidural anaesthesia in both groups; postop: PCEA 0.06% bupivacaine + 10 µg/ml hydromorphone; oral analgesics (hydrocodone/acetaminophen or oxycodone/acetaminophen) on day 2

At rest VAS: NS; during physical therapy VAS: Fem superior on days 1 and 2 (p<0.05, in both cases); proportion patients reporting VAS score ³6 during physical therapy: Fem superior on day 1 (p=0.045) and day 2 (p=0.0062)

__

PCEA–volume administered: NS

Functional outcomes

ROM: Fem superior on day 2 (p<0.05), but NS on days 1 or 3; ambulation distance, independent transfer, continuous passive motion flexion, use of walker, progression to cane, stair use: NS

Complications

Nausea, pruritus: NS

Hospital stay

Length of hospital stay: NS

Ng 2001(LoE 1)

12/12/12/12

Intra-op femoral nerve block with 30 ml 0.25% ropivacaine (LowRop) vs. femoral nerve block with 30 ml 0.5% ropivacaine (HighRop) vs. femoral nerve block with 30 ml 0.25% bupivacaine (Bup) vs. sham block with 30 ml saline (Cont)

Postop: PCA-morphine, IV; 1g oral acetaminophen every 6 h, starting 24 h after surgery

__

__

Cumulative morphine consumption: all treatment groups (LowRop, HighRop, Bup) superior to Cont at 1, 8, 24 and 48 h (p<0.05, in all cases); HighRop, Bup superior to Cont at 4 h (p<0.05, in both cases); NS between HighRop, LowRop and Bup

Pain

VRS pain scores (0=no pain, 3=severe pain)

At rest and on movement: all treatment groups (LowRop, HighRop, Bup) superior to Cont at 1, 4 and 8 h (p<0.01, in all cases); HighRop and Bup superior to Cont at 24 h (p<0.01, in both cases) and LowRop superior to Cont at 24 h (p<0.05); all comparisons NS at 48 h at rest; HighRop and Bup superior to Cont at 48 h (p<0.01 in both cases) and LowRop superior to Cont (p<0.05) on movement at 48 h; NS between HighRop, LowRop and Bup

Complications

PONV, pruritus, sedation: NS

Hospital stay

Length of hospital stay: NS

Adams 2002

(LoE 2)

21/21

At first expression of pain postop: femoral block with 40 ml 0.375% bupivacaine (Bup) vs. up to 0.2 mg/kg IV piritramide, until clear decrease in pain, then 100 mg rectal diclofenac and PCA IV piritramide (0.025 mg/kg bolus, 10-min lockout) (Cont)

Postop: femoral block or piritramide, dependent on study group

NS during the assessment period (0–180 min)

__

__

PONV

NS

Allen 1998

(LoE 1)

12/12

Postop femoral nerve block with 30 ml 0.25% bupivacaine with 1:400,000 epinephrine and sham sciatic nerve block (Fem) vs. sham femoral and sham sciatic injections (Cont)

Postop: PCA-morphine, IV

At rest: Fem superior for first 8 h post-PACU (p<0.05, in all cases); data incomplete after the 8-h measurement; NS during physical therapy

__

Fem superior on days 0 and 1 (p<0.02, in both cases), but NS on days 2 or 3

Complications

Nausea, sedation, pruritus: NS

WangH 2002

(LoE 1)

15/15

Postop 40 ml femoral nerve injection: 0.25% bupivacaine with 1:100,000 epinephrine (Fem) vs. saline (Cont)

Postop: PCA-morphine, IV

Fem superior at 1 h (PACU) (p<0.01); at rest and during rehab on day 1: Fem superior (p<0.01; p<0.05, respectively), but NS on days 2 and 3

__

Morphine requirements: Fem superior in PACU (p<0.01) and on day 1 (p<0.05), but NS on days 2 and 3; total morphine consumption: Fem superior (p<0.05)

Functional Outcomes

Ambulation: Fem superior (larger proportion in Bup able to ambulate to preset distance goals) (p<0.05); distance ambulated at discharge: Fem superior (p<0.01); knee flexion: Fem superior on day 2 (p<0.05), but NS on discharge

Complications

Overall incidence of morphine-related side-effects (e.g. nausea): NS

Hospital stay

Length of hospital stay: Fem superior (p<0.05)

*Study*	n treatment/ control	*Comparison*	*Supplemental* *analgesic*	*VAS scores and type of pain, where specified*	*Time to first analgesic request*	*Use of supplemental analgesic*	*Other important outcomes*
Hirst 1996(LoE 1)	11/11	Pre-op single injection femoral nerve block with 20 ml 0.5% bupivacaine and 1:200,000 epinephrine (Fem) *vs.* “mock” femoral nerve blocks (Cont)	Postop: PCA-morphine, IV	Fem superior during passive flexion (30°) in recovery room (p<0.05); NS at other time points recorded (i.e. in the next 72 h)	__	Morphine requirements: NS during assessment period (i.e. over 1^st 48 h postop)	PONV Nausea: Fem superior at 24 and 48 h (p values not reported)
Macalou 2004 (LoE 1)	29/28	Before induction of GA: femoral nerve block with 0.5% bupivacaine and 2% lidocaine (25 ml of LA solution injected) with 1:200,000 epinephrine (Fem) *vs.* 10 ml saline at site of femoral nerve (Cont)	Postop: PCA-morphine, IV	NS during assessment period (i.e. 1^st 6 h postop)	__	NS during assessment period (i.e. 1^st 6 h postop)	PONV NS Complications Respiratory depression: NS
Szczukowski 2004 (LoE 1)	19/21	Pre-op single injection femoral nerve block with 30 ml 0.5% bupivacaine and 1:200,000 epinephrine (Fem) *vs.* sham femoral nerve block with 30 ml saline (Cont)	Postop: PCA-morphine, IV; 5 mg oral oxycodone or 325 mg oral acetaminophen available every 4 h if required	Fem superior on day of surgery (day 0), (p=0.002), but NS on days 1 and 2; average pain score (days 0–2): Fem superior (p=0.013)	__	Morphine consumption: Fem superior on day 1 (p=0.003) and over the entire postop period (i.e. over days 0–3) (p=0.011)	PONV NS Functional outcomes Degree of ambulation, ROM: NS Complications Sedation: Fem superior on day 1 (p=0.045), but NS on days 2 and 3; pruritus, urinary retention, dizziness: NS Hospital stay Length of hospital stay: NS
YaDeau 2005 (LoE 1)	41/39	Pre-op :30 ml 0.375% bupivacaine with 5 µg/ml epinephrine into femoral sheath (Fem) vs. control (Cont)	Background analgesia: spinal-epidural anaesthesia in both groups; postop: PCEA 0.06% bupivacaine + 10 µg/ml hydromorphone; oral analgesics (hydrocodone/acetaminophen or oxycodone/acetaminophen) on day 2	At rest VAS: NS; during physical therapy VAS: Fem superior on days 1 and 2 (p<0.05, in both cases); proportion patients reporting VAS score ³6 during physical therapy: Fem superior on day 1 (p=0.045) and day 2 (p=0.0062)	__	PCEA–volume administered: NS	Functional outcomes ROM: Fem superior on day 2 (p<0.05), but NS on days 1 or 3; ambulation distance, independent transfer, continuous passive motion flexion, use of walker, progression to cane, stair use: NS Complications Nausea, pruritus: NS Hospital stay Length of hospital stay: NS
Ng 2001(LoE 1)	12/12/12/12	Intra-op femoral nerve block with 30 ml 0.25% ropivacaine (LowRop) vs. femoral nerve block with 30 ml 0.5% ropivacaine (HighRop) vs. femoral nerve block with 30 ml 0.25% bupivacaine (Bup) *vs.* sham block with 30 ml saline (Cont)	Postop: PCA-morphine, IV; 1g oral acetaminophen every 6 h, starting 24 h after surgery	__	__	Cumulative morphine consumption: all treatment groups (LowRop, HighRop, Bup) superior to Cont at 1, 8, 24 and 48 h (p<0.05, in all cases); HighRop, Bup superior to Cont at 4 h (p<0.05, in both cases); NS between HighRop, LowRop and Bup	Pain VRS pain scores (0=no pain, 3=severe pain) At rest and on movement: all treatment groups (LowRop, HighRop, Bup) superior to Cont at 1, 4 and 8 h (p<0.01, in all cases); HighRop and Bup superior to Cont at 24 h (p<0.01, in both cases) and LowRop superior to Cont at 24 h (p<0.05); all comparisons NS at 48 h at rest; HighRop and Bup superior to Cont at 48 h (p<0.01 in both cases) and LowRop superior to Cont (p<0.05) on movement at 48 h; NS between HighRop, LowRop and Bup Complications PONV, pruritus, sedation: NS Hospital stay Length of hospital stay: NS
Adams 2002 (LoE 2)	21/21	At first expression of pain postop: femoral block with 40 ml 0.375% bupivacaine (Bup) *vs.* up to 0.2 mg/kg IV piritramide, until clear decrease in pain, then 100 mg rectal diclofenac and PCA IV piritramide (0.025 mg/kg bolus, 10-min lockout) (Cont)	Postop: femoral block or piritramide, dependent on study group	NS during the assessment period (0–180 min)	__	__	PONV NS
Allen 1998 (LoE 1)	12/12	Postop femoral nerve block with 30 ml 0.25% bupivacaine with 1:400,000 epinephrine and sham sciatic nerve block (Fem) *vs.* sham femoral and sham sciatic injections (Cont)	Postop: PCA-morphine, IV	At rest: Fem superior for first 8 h post-PACU (p<0.05, in all cases); data incomplete after the 8-h measurement; NS during physical therapy	__	Fem superior on days 0 and 1 (p<0.02, in both cases), but NS on days 2 or 3	Complications Nausea, sedation, pruritus: NS
WangH 2002 (LoE 1)	15/15	Postop 40 ml femoral nerve injection: 0.25% bupivacaine with 1:100,000 epinephrine (Fem) *vs.* saline (Cont)	Postop: PCA-morphine, IV	Fem superior at 1 h (PACU) (p<0.01); at rest and during rehab on day 1: Fem superior (p<0.01; p<0.05, respectively), but NS on days 2 and 3	__	Morphine requirements: Fem superior in PACU (p<0.01) and on day 1 (p<0.05), but NS on days 2 and 3; total morphine consumption: Fem superior (p<0.05)	Functional Outcomes Ambulation: Fem superior (larger proportion in Bup able to ambulate to preset distance goals) (p<0.05); distance ambulated at discharge: Fem superior (p<0.01); knee flexion: Fem superior on day 2 (p<0.05), but NS on discharge Complications Overall incidence of morphine-related side-effects (e.g. nausea): NS Hospital stay Length of hospital stay: Fem superior (p<0.05)